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Experiment Manual

Maharastra EXTC NetSim Experiment Manual

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Page 1: Maharastra EXTC  NetSim Experiment  Manual

Experiment Manual

Page 2: Maharastra EXTC  NetSim Experiment  Manual

The information contained in this document represents the current view of TETCOS on the

issues discussed as of the date of publication. Because TETCOS must respond to changing

market conditions, it should not be interpreted to be a commitment on the part of TETCOS,

and TETCOS cannot guarantee the accuracy of any information presented after the date of

publication.

This manual is for informational purposes only. TETCOS MAKES NO WARRANTIES,

EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS

DOCUMENT.

Warning! DO NOT COPY

Copyright in the whole and every part of this manual belongs to TETCOS and may not be

used, sold, transferred, copied or reproduced in whole or in part in any manner or in any

media to any person, without the prior written consent of TETCOS. If you use this manual

you do so at your own risk and on the understanding that TETCOS shall not be liable for any

loss or damage of any kind.

TETCOS may have patents, patent applications, trademarks, copyrights, or other intellectual

property rights covering subject matter in this document. Except as expressly provided in any

written license agreement from TETCOS, the furnishing of this document does not give you

any license to these patents, trademarks, copyrights, or other intellectual property. Unless

otherwise noted, the example companies, organizations, products, domain names, e-mail

addresses, logos, people, places, and events depicted herein are fictitious, and no association

with any real company, organization, product, domain name, email address, logo, person,

place, or event is intended or should be inferred.

Rev 9.0 (MAH EXTC), October 2016 , TETCOS. All rights reserved.

All trademarks are property of their respective owner.

Contact us at –

TETCOS

214, 39th A Cross, 7th Main, 5th Block Jayanagar,

Bangalore - 560 041, Karnataka, INDIA. Phone: +91 80 26630624

E-Mail: [email protected]

Visit: www.tetcos.com

Page 3: Maharastra EXTC  NetSim Experiment  Manual

Contents

ETC 702 MOBILE COMMUNICATION ........................................................... 6

Introduction to Wireless Communication .............................................. 6 1.

Orthogonal Frequency Division Multiple Access .................................... 6 2.

To study the working of Time Division Multiple Access technique ...... 12 3.

Study how call blocking probability varies as the load on a GSM 4.

network is continuously increased. .............................................................. 15

GSM Network Architecture ................................................................. 19 5.

Introduction to GSM frame structure .................................................. 19 6.

Protocol Architecture .......................................................................... 19 7.

Call Procedure ..................................................................................... 19 8.

Handoff Procedure ............................................................................. 19 9.

Analysis of GSM Handover .................................................................. 20 10.

CDMA Network Architecture ............................................................... 24 11.

Forward and Reverse channel In CDMA ............................................. 24 12.

Establishing a Connection In 3G System .............................................. 24 13.

Page 4: Maharastra EXTC  NetSim Experiment  Manual

Handover in CDMA ............................................................................. 24 14.

Study how the number of channels increases and the Call blocking 15.

probability decreases as the Voice activity factor of a CDMA network is

decreased .................................................................................................... 25

To Study how the throughput of LTE network varies as the distance 16.

between the ENB (Evolved node B) and UE (User Equipment) is increased .. 29

Study how the throughput of LTE network varies as the Channel 17.

bandwidth changes in the ENB (Evolved node B) ......................................... 35

Analysis of LTE Handover .................................................................... 41 18.

Study how the Data Rate of a Wireless LAN (IEEE 802.11b) network 19.

varies as changing Wireless Channel Characteristics . .................................. 46

ETC 801 WIRELESS NETWORK .................................................................... 52

Introduction to GSM ........................................................................... 52 20.

Analyze the scenario shown, where Node 1 transmits data to Node 2, 21.

with no path loss and obtain the theoretical throughput based on IEEE

802.15.4 standard. Compare this with the simulation result. ....................... 52

Mobility Models in Wi-MAX (IEEE 802.16e/m) Network ...................... 58 22.

Study the SuperFrame Structure and analyze the effect of SuperFrame 23.

order on throughput. ................................................................................... 63

ETC 803 INTERNET AND VOICE COMMUNICATION ........................................ 68

TCP/IP Networking model ................................................................... 68 24.

Page 5: Maharastra EXTC  NetSim Experiment  Manual

Internet Layering and ISO Model ......................................................... 68 25.

Understand IP forwarding within a LAN and across a router ............... 68 26.

Dynamic Host Configuration Protocol ................................................. 75 27.

Configure and analyze the TCP versus UDP response Time With HTTP 28.

Application .................................................................................................. 78

Page 6: Maharastra EXTC  NetSim Experiment  Manual

ETC 702 MOBILE COMMUNICATION

Introduction to Wireless Communication 1.

Refer: Study theory from NetSim ”Basic Menu Internetwork Wireless LAN “

Orthogonal Frequency Division Multiple 2.

Access

Programming Guidelines

This section guides the user to link his/her own code for Orthogonal Frequency Division

Multiple Access to NetSim.

Pre-conditions

The user program should read the input scenario from text file named „Input‟ with extension

txt which is in Temporary Directory.

The user program after executing the concept should write the required output to a file named

„Output’ with extension txt in Temporary Directory.

Note: The temporary directory is navigated through the following step.

Run Type "%temp%" NetSim "Input.txt" and "Output.txt"

( Note: For Run Press Windows + R)

General Program Flow

The program begins with the Reading of the Inputs from the input file Input.txt.

Executing the required concept and, the results of the program should be written into the

output file Output.txt.

Page 7: Maharastra EXTC  NetSim Experiment  Manual

Input File Format Output File Format

The following lines will be

in Input.txt file.

Number of users = Value

User1 =Value

User2 =Value

User3 =Value

User4 =Value

Number of sub carrier per

user = Value

Example:

Number of users = 4

User1 =111111111111

User2 =010101010101

User3 =101010101010

User4 =000000000000

Number of sub carrier per

user = 4

Parallel Data Conversion

User 1

Value

User 2

Value

User 3

Value

User 4

Value

Bit Mapping

User 1

Value

User 2

Value

User 3

Value

User 4

Value

SubCarrier Mapping

User 1

Value

User 2

-Value

User 3

Value

User 4

Value

SubCarrier Addition

User 1

Page 8: Maharastra EXTC  NetSim Experiment  Manual

Value

User 2

Value

User 3

Value

User 4

Value

Example:

Parallel Data Conversion

User 1

1 1 1 1

1 1 1 1

1 1 1 1

User 2

0 1 0 1

0 1 0 1

0 1 0 1

User 3

1 0 1 0

1 0 1 0

1 0 1 0

User 4

0 0 0 0

0 0 0 0

0 0 0 0

Bit Mapping

User 1

1 1 1 1

1 1 1 1

1 1 1 1

User 2

Page 9: Maharastra EXTC  NetSim Experiment  Manual

-1 1 -1 1

-1 1 -1 1

-1 1 -1 1

User 3

1 -1 1 -1

1 -1 1 -1

1 -1 1 -1

User 4

-1 -1 -1 -1

-1 -1 -1 -1

-1 -1 -1 -1

SubCarrier Mapping

User 1

sin(2PIf0t) sin(2PIf1t) sin(2PIf2t) sin(2PIf3t)

sin(2PIf0t) sin(2PIf1t) sin(2PIf2t) sin(2PIf3t)

sin(2PIf0t) sin(2PIf1t) sin(2PIf2t) sin(2PIf3t)

User 2

-sin(2PIf4t) sin(2PIf5t) -sin(2PIf6t) sin(2PIf7t)

-sin(2PIf4t) sin(2PIf5t) -sin(2PIf6t) sin(2PIf7t)

-sin(2PIf4t) sin(2PIf5t) -sin(2PIf6t) sin(2PIf7t)

User 3

sin(2PIf8t) -sin(2PIf9t) sin(2PIf10t) -sin(2PIf11t)

sin(2PIf8t) -sin(2PIf9t) sin(2PIf10t) -sin(2PIf11t)

sin(2PIf8t) -sin(2PIf9t) sin(2PIf10t) -sin(2PIf11t)

User 4

-sin(2PIf12t) -sin(2PIf13t) -sin(2PIf14t) -sin(2PIf15t)

-sin(2PIf12t) -sin(2PIf13t) -sin(2PIf14t) -sin(2PIf15t)

-sin(2PIf12t) -sin(2PIf13t) -sin(2PIf14t) -sin(2PIf15t)

SubCarrier Addition

User 1

sin 2PI(f0+f1+f2+f3)t

sin 2PI(f0+f1+f2+f3)t

Page 10: Maharastra EXTC  NetSim Experiment  Manual

sin 2PI(f0+f1+f2+f3)t

User 2

sin 2PI(-f4+f5-f6+f7)t

sin 2PI(-f4+f5-f6+f7)t

sin 2PI(-f4+f5-f6+f7)t

User 3

sin 2PI(f8-f9+f10-f11)t

sin 2PI(f8-f9+f10-f11)t

sin 2PI(f8-f9+f10-f11)t

User 4

sin 2PI(-f12-f13-f14-f15)t

sin 2PI(-f12-f13-f14-f15)t

sin 2PI(-f12-f13-f14-f15)t

Interface Source Code

Interface Source code written in C is given. Using this, the user can write only the

fnOFDMA() and fnSubcarrierAddition() functions, using the variables already declared.To

view the interface source code, go to

NetSim Installation path/src/Programming/OFDMA.c

To find NetSim‟s Installation path right click NetSim icon and select

Open file location in Windows 7

Open file location in Windows Vista

Properties find target in Windows XP.

Sample Scenarios:

Objective - To study the working of Orthogonal Frequency Division Multiple Access

technique

How to Proceed? - The objective can be executed in NetSim using the programming

exercise available. Under programming select Multiple Access Technology OFDMA

Page 11: Maharastra EXTC  NetSim Experiment  Manual

Sample Inputs - In the Input panel,

Sample Mode should be selected.

The value of Number of Users needs to be selected.

Enter the Binary Datafor each user.

Number of SubCarriers per User needs to be selected.

Then Run button needs to be clicked. Refresh button can be used if new Inputs have to

be given.

Output - The following steps are done internally by NetSim

The values of each userBinary Data, Parallel Conversion, Bit Mapping, SubCarrier

Mapping&SubCarrier Addition and Transmission will be shown in the right hand

side of the screen by animation.

Once the sample experiment is done Refresh button can be clicked to create new

samples.

Page 12: Maharastra EXTC  NetSim Experiment  Manual

To study the working of Time Division Multiple 3.

Access technique

3.1 How to Proceed:

The objective can be executed in NetSim using the programming exercise available, under programming

user has to select Multiple Access Technology Time Division Multiple Access.

3.2 Sample Inputs:

In the Input panel the following steps need to be done,

Sample Mode should be selected.

Enter the Value of the Bandwidth.

Enter the Value of the No. of Time Slots.

Enter the Value of the TimeSlotLength.

Enter the Value of the GuardInterval

Note: The Values entered should be within the range.

Bandwidth(kHz) 200

No. of TimeSlots 3

TimeSlotLength(µs) 100

GuardInterval(µs) 10

Then Run button need to be clicked. Refresh button can be used, if new

Inputs have to be given.

Page 13: Maharastra EXTC  NetSim Experiment  Manual

3.3 Output:

The Output for the above sample is as follows,

Bandwidth is divided into Time slots called channel.

The first channel is allocated to first mobile station, second channel is

allocated to second mobile station and so on.

The first Mobile Station will access the medium in first channel time slot.

The Second Mobile Station will access the medium in second channel

time slot, and so on.

During the guard interval, No mobile station will access the medium. This

is used to avoid the collision or interference.

Finally the table will be showed as follows,

Channel no. is obtained.

Bandwidth value is obtained.

Start Time and End Time of the Guard Interval is obtained

Start Time and End Time of the channel is obtained.

Which Mobile Station is accessing the allocated time slot is obtained.

Channel number Bandwidth(kHz) Time(µs) Mobile Station

0 200 0.0 – 5.0 0

1 200 5.0 – 95.0 1

0 200 95.0 – 100.0 0

0 200 100.0 – 105.0 0

2 200 105.0 – 195.0 2

0 200 195.0 – 200.0 0

0 200 200.0 – 205.0 0

3 200 205.0 – 295.0 3

0 200 295.0 – 300.0 0

Page 14: Maharastra EXTC  NetSim Experiment  Manual

0 200 300.0 – 305.0 0

1 200 305.0 – 395.0 1

Page 15: Maharastra EXTC  NetSim Experiment  Manual

Study how call blocking probability varies as the load on a 4.

GSM network is continuously increased.

4.1 Procedure:

In NetSim, Select “Simulation New Cellular Networks GSM”

Follow the steps given in the different samples to arrive at the objective.

In this Experiment,

One BTS (BTS A) and one MSC (MSC B) is used

Total no of MS used: Vary from 4 to 20 in steps of 2.

The devices are inter connected as given below,

All the MS are placed in the range of BTS A

Set the properties by following the tables for each sample,

Inputs for Sample 1

Number of MS = 4

Page 16: Maharastra EXTC  NetSim Experiment  Manual

Accept default properties for BTS.

Edit Uplink Bandwidth Min to 890 MHz and Uplink Bandwidth Max to 890.2 MHz in

MSC properties.

In the Sample 1, two Applications are run. After dropping Application on the Environment

menu, add application 2 from the left pane and change the following properties:

Application Properties Application 1 Application2

Application type Erlang_call Erlang_call

Source_Id 3 5

Destination_Id 4 6

Call

Duration_ Distribution Exponential Exponential

Duration(s) 60 60

Inter Arrival Time (sec) 10 10

IAT_ Distribution Exponential Exponential

Codec

Codec Custom Custom

Service Type CBR CBR

Packet Size 33 33

Inter Arrival Time (µs) 20000 20000

Page 17: Maharastra EXTC  NetSim Experiment  Manual

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1 2 3 4 5 6 7 8 9

Cal

l Blo

ckin

g P

rob

abili

ty

Sample Number

Simulation Time – 100 sec

Inputs for Sample 2

Number of MS = 6

Add one more Application and set the properties as above with Source_Id as 7 and

Destination_Id as 8.

Likewise, increase the number of MS by 2 upto 20 and set properties for different Samples

by adding an application every time and changing Source_Id and Destination_Id.

Simulation Time – 100 sec

4.1.1 Output

To view the output, go to the Cellular Metrics.

In MS metrics, add the call blocked and call generated column. Call blocking probability is

calculated as ratio of Total call blocked to Total call generated.

Comparison Charts

*** All the above plots highly depend upon the placement of Mobile station in the simulation

environment. So, note that even if the placement is slightly different the same set of values

will not be got but one would notice a similar trend.

Page 18: Maharastra EXTC  NetSim Experiment  Manual

4.1.2 Inference:

When the number of MS is increased from 4 to 20 the call blocking probability increases

from 0 to 0.88. As we increase the number of mobile stations more calls are generated. This

increases the traffic load on the system & more calls generated implies more channel requests

arrive at the base station but the number of channels is fixed. So when the base station does

not find any free channel the call is blocked.

An additional observation is that the call blocking is zero until 8 MS. This is because the

number of channels is sufficient to handle all call that 6 MS may generate. Only after this the

base station does not find free channels and blocks calls.

Page 19: Maharastra EXTC  NetSim Experiment  Manual

GSM Network Architecture 5.

Refer: Study theory from NetSim “Basic Menu Cellular Network GSM

Architecture “

Introduction to GSM frame structure 6.Refer: Study theory from NetSim “Basic Menu Cellular Network GSM

Frame Structure “

Protocol Architecture 7.Refer: Study theory from NetSim” Basic Menu Cellular Network GSM

Protocols”

Call Procedure 8.Refer: Study theory from NetSim” Basic Menu Cellular Network GSM Call

Flow “

Handoff Procedure 9.Refer: Study theory from NetSim “Basic Menu Cellular Network GSM

Handover “

Page 20: Maharastra EXTC  NetSim Experiment  Manual

Analysis of GSM Handover 10.

10.1 Theory

GSM (Global System for Mobile communications) is an open, digital cellular technology

used for transmitting mobile voice and data services.

10.2 Procedure

Step 1:

In NetSim, Select “Simulation New Cellular

Networks GSM

Step 2:

Click & drop 2 Base Station ,1 MSC and 2 Mobile

Station on the Simulation Environment as shown and

link them.

Step 3:

Arrange the positions of the Base Station as per the following table:

Base Station X-Coordinate Y-Coordinate

2 1000 1000

3 2000 1000

Page 21: Maharastra EXTC  NetSim Experiment  Manual

Arrange the positions of Mobile Station as per the following table:

Mobile Station X-Coordinate Y-Coordinate

4 500 1000

5 1500 1000

Step 4:

Mobile Station Properties: Right click on the Mobile Station and set Velocity 1 m/s for

Mobile Station 4 and 100m/s for Mobile Station 5

Application Properties

Application Type ERLANG_CALL

Source_Id 4(Mobile Station D)

Destination_Id 5(Mobile Station E)

Call

Call Duration 1000 Sec

Inter Arrival Time 1 Sec

Page 22: Maharastra EXTC  NetSim Experiment  Manual

Step 4:

Simulation Time - 250 sec

(Note: The Simulation Time can be selected only after doing the following two tasks,

Set the properties of Mobile Station

Then click on Run Simulation button).

10.3 Output

Open Packet Animation:

Due to Mobility Mobile Stations can move from one cell to another. In the below figure,

users can see the handover packet flow in packet animation

Page 23: Maharastra EXTC  NetSim Experiment  Manual

As shown in the above packet animation, MS D connected to BTS B and MS E

connected to BTS C

MS E is moving from BTS C to BTS B due to mobility Which Causes Handover

Then MS E Sends GSM_Channel_Request_For_Handover to BTS B

In Response, The BTS B checks for resource availability and sends a

GSM_Channel_Granted to the MS E

10.4 Inference

Firstly MS E is communicating with BTS C. Due to mobility MS E moves from one cell to

another. So Handover occurs. Now MS E starts communicating with BTS B.

Page 24: Maharastra EXTC  NetSim Experiment  Manual

CDMA Network Architecture 11.

Refer: Study theory from NetSim “Basic Menu Cellular Network CDMA

Architecture “

Forward and Reverse channel In CDMA 12.Refer: Study theory from NetSim” Basic Menu Cellular Network CDMA

Channels”

Establishing a Connection In 3G System 13.Refer: Study theory from NetSim ” Basic Menu Cellular Network CDMA

Call flow diagram”

Handover in CDMA 14.Refer: Study theory from NetSim “Basic Menu Cellular Network CDMA

Handover”

Page 25: Maharastra EXTC  NetSim Experiment  Manual

Study how the number of channels increases 15.

and the Call blocking probability decreases as

the Voice activity factor of a CDMA network is

decreased

15.1 Procedure:

How to Create Scenario & Generate Traffic:

In NetSim, Select “Simulation New Cellular Networks CDMA”

Please navigate through the below given path to understand,

Inputs

Follow the steps given in the different samples to arrive at the objective.

In all Samples,

Total no of BTS used: 1

Total no of MSC used: 1

Total no of MS used: 60

The devices are interconnected as given below,

All the MS are placed in the range of BTS A ( default 1 Km)

BTS A is connected via Wired Link to MSC B

Sample 1: Drop 1 BTS, 1 MSC and 60 MS and interconnect them in no specific order.

Page 26: Maharastra EXTC  NetSim Experiment  Manual

Application

Properties

Application

1

Application

2

Application

3

Application

4

Application

5

Source_Id 3 5 7 9 11

Destination_Id 4 6 8 10 12

All other

Properties Default Default Default Default Default

Likewise add 25 more applications (totaling 30) with above properties and Source_Id13 to

Destination_Id 14 for application 6… and Source_Id 61 to Destination_Id 62 for application

30.

We have considered MSC to be device ID 1, and BTS as device ID 2.

Simulation Time – 500 sec

Set Packet Animation to Don’t play/record animation (Simulation will run fast) and click

OK. If record animation option is selected, the simulation may take a long time to complete.

Upon completion of the experiment “Save” the experiment

Sample 2:

Keep all properties same as Sample 1 and in the BTS properties, change the voice activity

factor to 0.9 as shown:

Page 27: Maharastra EXTC  NetSim Experiment  Manual

Sample 3 and so on: Change the voice activity factor to 0.8 in sample 3, 0.7 in sample 4….

and to 0.1 in sample 10 in BTS properties.

15.2 Output

To view the output, go to the Cellular Metrics.

In Channel metrics, the channel count is mentioned.

For every sample plot the graph.

Comparison Charts and Inference:

0

50

100

150

200

250

300

350

400

450

1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1

Ch

ann

el C

ou

nt

Voice Activity Factor

Page 28: Maharastra EXTC  NetSim Experiment  Manual

When the system Voice activity factor decreases from 1.0 to 0.1, the number of channels

increases from 3 to 30.

In CDMA network, the number of channels is inversely proportional to the voice activity

factor.

Chart 1 is a mirrored form of graph. (This is because VAF is decreasing along +ve X)

In MS metrics, the call generated and call blocked is shown for each MS. Add all the calls

generated to obtain Total call generated, and add calls blocked for all MS Ids to obtain Total

call blocked.

Calculate call blocking probability as ratio of Total call blocked to Total call generated.

When voice activity factor is decreased the number of channels available increases. Thus the

system has more number of channels to handle the same number of calls (Note - Number of

MS is constant and their properties are same across all experiments. So, they generate

approximately same number of calls throughout). As the number of channels increase the

call blocking probability decreases.

xy

1

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1

Cal

l Blo

ckin

g P

rob

abili

ty

Voice Activity Factor

Page 29: Maharastra EXTC  NetSim Experiment  Manual

To Study how the throughput of LTE network 16.

varies as the distance between the ENB

(Evolved node B) and UE (User Equipment) is

increased

16.1 Theory:

LTE or Long Term Evolution, commonly known as 4G LTE, is a standard for wireless

communication of high-speed data for mobile phones and data terminals. It is based on the

GSM/EDGE and UMTS/HSPA network technologies, increasing the capacity and speed

using a different radio interface.

The path loss in LTE is the decay of the signal power dissipated due to radiation on the

wireless channels. Path loss may be due to many effects, such as free space loss, refraction,

diffraction, reflection, aperture-medium coupling loss, and absorption.

Received power (Pr) can be calculated as:

Case 1: When no path loss Received power is same as Transmitted power, i.e., Pr = Pt

Case 2: When Line of Sight is there, Received power Pr is

Pr = Pt + Gt + Gr +

+

Where Gt and Gr are gains of transmitting and receiving antenna respectively. Here d is the

distance between transmitter and receiver, λ is the wavelength of the transmitted signal and

is reference distance at which channel gain becomes 1. n is path loss exponent and Pt is

transmitted power.

Page 30: Maharastra EXTC  NetSim Experiment  Manual

16.2 Procedure:

16.2.1 How to Create Scenario & Generate Traffic:

Create Scenario: Please refer “Help NetSim User Manual F1 Section 3.10 LTE”.

16.2.2 Sample Inputs:

In this experiment, 1 Router, 1 Wired Node and 1 MME , 1 UE and 1 ENB is clicked and

dropped onto the Simulation environment from tool bar as shown below.

Sample 1:

These properties can be set only after devices are linked to each other as shown above.

Wired Node Properties:

Node Properties Wired Node A

Transport Layer Properties

TCP Disable

Router Properties: Default properties.

MME Properties: Default properties.

ENB Properties:

ENB Properties ENB 4

Global Properties

X_Coordinate 0

Y_Coordinate 0

Page 31: Maharastra EXTC  NetSim Experiment  Manual

UE Properties:

UE Properties UE D

Global Properties

X_Coordinate 50

Y_Coordinate 50

Velocity(m/s) 0

To run the simulation, drop the Application icon and change the following properties:

Application Properties

Application Type Custom

Source ID 1 (Wired Node A)

Destination ID 5 (UE D)

Packet Size

Distribution Constant

Value(Bytes) 1460

Inter Arrival Time

Distribution Constant

Value(µs) 165

Wired Link Properties:

Link Properties Wired Link 1 Wired Link 2 Wired Link 3

Uplink Speed (Mbps) 100 100 100

Downlink Speed (Mbps) 100 100 100

Uplink BER No Error No Error No Error

Downlink BER No Error No Error No Error

Page 32: Maharastra EXTC  NetSim Experiment  Manual

Wireless Link Properties:

Link Properties Wireless Link 4

Channel characteristics Line of Sight

Path loss Exponent(n) 4

Simulation Time – 10 Sec

(Note: The Simulation Time can be selected only after the following two tasks,

Set the properties for the Wired Node, Router, MME, UE, Wired, Wireless Links and

Application.

Click on Run Simulation).

Upon completion of the experiment “Save” the experiment and note down the Application

throughput which is available in Application metrics for each sample case.

Sample 2:

Change the following properties in UE and run the simulation for 10 seconds as above. All

other properties are default.

UE Properties:

UE Properties UE D

Global Properties

X_Coordinate 100

Y_Coordinate 100

Velocity(m/s) 0

From Sample 3 to Sample 9:

Change the UE property every time (for all samples) by varying the (x, y) coordinates values

as follows:

Page 33: Maharastra EXTC  NetSim Experiment  Manual

Change in UE Properties: (x, y)

Sample 3 (150,150)

Sample 4 (200,200)

Sample 5 (250,250)

Sample 6 (300,300)

Sample 7 (350,350)

Sample 8 (400,400)

Sample 9 (450,450)

And note down the throughput values from the Application metrics in each sample case.

16.2.3 Output:

Step 1: Distance calculation:

Calculate the Distance between ENB (x1, y1) and UE(x2, y2) as follows: √(x2-x1)2+ (y2-y1)

2

For example for Sample 1:

ENB (x1, y1) = (0, 0); UE(x2, y2) = (50, 50);

Distance = √ (50-0)2+ (50-0)

2 = √2 × 50 = 50√2 meters.

Step 2:

Open the Excel file and note down the distance between UE and ENB and throughput values

as shown in below table.

Sample nos.

Sample Number

Distance between UE and

ENB (meters)

Throughput (Mbps)

1 50√2 = 70.71

70.774960

2 100√2 = 140.42

70.204976

3 150√2 = 212.13

62.544064

4 200√2 = 282.84

50.447088

5 250√2 = 353.55

30.223168

6 300√2 = 424.26

19.603712

7 350√2 = 494.97

15.645360

Page 34: Maharastra EXTC  NetSim Experiment  Manual

8 400√2 = 565.68

8.642032

9 450√2 = 636.39

4.468768

16.2.4 Comparison Chart

To draw these graphs by using Excel “Insert Chart” option and then select chart type as

“Column Chart”.

16.2.5 Inference

As the distance increases between ENB and UE, throughput value is getting decreased. The

reason is if distance increases between the devices, the received signal power will be

decreased due to high path loss.

0

10

20

30

40

50

60

70

80

70.71 140.42 212.13 282.84 353.55 424.26 494.97 565.68 636.39

Thro

ughput(

Mbps)

Distance (Meters)

Page 35: Maharastra EXTC  NetSim Experiment  Manual

Study how the throughput of LTE network 17.

varies as the Channel bandwidth changes in

the ENB (Evolved node B)

17.1 Theory:

LTE or Long Term Evolution, commonly known as 4G LTE, is a standard for wireless

communication of high-speed data for mobile phones and data terminals. It is based on the

GSM/EDGE and UMTS/HSPA network technologies, increasing the capacity and speed

using a different radio interface.

LTE supports flexible carrier bandwidths, from 1.4 MHz up to 20 MHz as well as both FDD

and TDD. LTE designed with a scalable carrier bandwidth from 1.4 MHz up to 20 MHz

which bandwidth is used depends on the frequency band and the amount of spectrum

available with a network operator.

17.2 Procedure:

Create Scenario: Go to Simulation New LTE Networks.

Sample Inputs:

In this experiment, 1 Wired Node ,1 Router, 1 MME , 1 ENB and 3 UE are clicked and

dropped onto the Simulation environment from tool bar as shown.

Page 36: Maharastra EXTC  NetSim Experiment  Manual

Sample 1:

Note: These properties can be set only after devices are linked to each other as shown above.

Wired Node Properties:

Node Properties Wired Node A

Transport Layer Properties

TCP Disable

Router Properties: Default properties.

MME Properties: Default properties.

ENB Properties:

ENB Properties ENB D

Interface_LTE (Physical Layer)

Channel Bandwidth (MHz) 20

To run the simulation, drop the Application icon and change the following properties:

Application

Properties

Application

1

Application

2

Application

3

Application Type Custom Custom Custom

Source ID 1 (Wired

Node A)

1 (Wired

Node A)

1 (Wired

Node A)

Destination ID 5(UE E) 6(UE F) 7(UE G)

Packet Size

Distribution Constant Constant Constant

Value(Bytes) 1460 1460 1460

Inter Arrival Time

Distribution Constant Constant Constant

Value(µs) 146 146 146

Page 37: Maharastra EXTC  NetSim Experiment  Manual

UE Properties:

UE Properties UE E UE F UE G

Global Properties

Velocity(m/s) 0 0 0

Wired Link Properties:

Link Properties Wired Link 2 Wired Link 3 Wired Link 4

Uplink Speed (Mbps) 1000 1000 1000

Downlink Speed (Mbps) 1000 1000 1000

Uplink BER 0 0 0

Downlink BER 0 0 0

Wireless Link Properties:

Link Properties Wireless Link 1

Channel characteristics No Path Loss

Simulation Time – 10 Sec

(Note: The Simulation Time can be selected only after the following two tasks,

Set the properties for the Wired Node, Router, MME, UE, Wired, Wireless Links and

Application.

Click on Run Simulation).

Upon completion of the experiment “Save” the experiment and note down the Application

throughputs of all applications which is available in Application metrics for each sample

case.

Page 38: Maharastra EXTC  NetSim Experiment  Manual

Sample 2:

Change the following properties in ENB and run the simulation for 10 seconds as above. All

other properties are default.

ENB Properties ENB D

Interface_LTE (Physical Layer)

Channel Bandwidth (MHz) 15

From Sample 3 & Sample 4:

Change the ENB property, Channel Bandwidth to 10, 5, 3, 1.4 MHz (Refer below table)

Sample Channel Bandwidth(MHz)

3 10

4 5

And note down the throughput values from the Application metrics in each sample case.

17.3 Output:

Step 1: Add the sum of all throughput values in each sample case:

Example:

Sample 1: Application ID Throughput (mbps)

1 24.846864

2 24.848032

3 24.848032

Sum = 74.542928 mbps.

Same procedure for all other sample cases also.

Page 39: Maharastra EXTC  NetSim Experiment  Manual

0

20

40

60

80

20 15 10 5

Thro

ughput(

Mbps)

Channel Bandwidth(MHz)

Step 2: Open the Excel file and note down the sum of applications throughput values as

shown in below table.

Sample nos.

Sample Number

Channel

Bandwidth(MHz)

Throughput (Mbps)

1 20 74.542928

2 15 52.160544

3 10 34.766688

4 5 17.351808

Comparison Chart:

To draw these graphs by using Excel “Insert Chart” option and then select chart type as

“Line chart”.

17.4 Inference

The LTE solution provides spectrum flexibility with scalable transmission bandwidth

between 1.4 MHz and 20 MHz depending on the available spectrum for flexible radio

planning. The 20 MHz bandwidth can provide up to 150 Mbps downlink user data rate and

75 Mbps uplink peak data rate with 2×2 MIMO, and 300 Mbps with 4×4 MIMO.

As the channel bandwidth decreases the number of resource blocks also decreases. If more

resource blocks are available then more number of packets can be transmitted.

Page 40: Maharastra EXTC  NetSim Experiment  Manual
Page 41: Maharastra EXTC  NetSim Experiment  Manual

Analysis of LTE Handover 18.

18.1 Introduction

Handover is an important function that maintains seamless connectivity when transitioning

from one base station to another.

18.2 LTE Handover Call Flow Description

1. A data call is established between the UE, S-eNB (Source-eNB) and the network

elements. Data packets are transferred to/from the UE to/from the network in both

directions (Downlink as well as Uplink)

2. The network sends the MEASUREMENT CONTROL REQ message to the UE to set

the parameters to measure and set thresholds for those parameters. Its purpose is to

instruct the UE to send a measurement report to the network as soon as it detects the

thresholds.

3. The UE sends the MEASUREMENT REPORT to the S-eNB after it meets the

measurement report criteria communicated previously. The S-eNB makes the

decision to hand off the UE to a T-eNB (Target-eNB) using the handover algorithm;

each network operator could have its own handover algorithm.

4. The S-eNB issues the RESOURCE STATUS REQUEST message to determine the

load on T-eNB (this is optional). Based on the received RESOURCE STATUS

RESPONSE, the S-eNB can make the decision to proceed further in continuing the

handover procedure using the X2 interface.

5. The S-eNB issues a HANDOVER REQUEST message to the T-eNB passing

necessary information to prepare the handover at the target side

6. The T-eNB checks for resource availability and, if available, reserves the resources

and sends back the HANDOVER REQUEST ACKNOWLEDGE message including

a transparent container to be sent to the UE as an RRC message to perform the

handover.

7. The S-eNB generates the RRC (Radio resource control->used for signalling transfer)

message to perform the handover, i.e., RRC CONNECTION RECONFIGURATION

Page 42: Maharastra EXTC  NetSim Experiment  Manual

message including the mobility Control Information. The S-eNB performs the

necessary integrity protection and ciphering of the message and sends it to the UE.

8. The S-eNB starts forwarding the downlink data packets to the T-eNB for all the data

bearers (which are being established in the T-eNB during the HANDOVER REQ

message processing).

9. In the meantime, the UE tries to access the T-eNB cell using the non-contention-

based Random Access Procedure. If it succeeds in accessing the target cell, it sends

the RRC CONNECTION RECONFIGURATION COMPLETE to the T-eNB.

10. The T-eNB now requests the S-eNB to release the resources. With this, the handover

procedure is complete.

Due to mobility UEs can move from one place to another

As shown in the above image, User Equipment is moving from Source-eNB to the

Target-eNB

Then UE sends the MEASUREMENT REPORT to the S-eNB

The S-eNB issues a HANDOVER REQUEST message to the T-eNB

The T-eNB checks for resource availability and, if available, reserves the resources

and sends back the HANDOVER REQUEST ACKNOWLEDGE message

Page 43: Maharastra EXTC  NetSim Experiment  Manual

18.3 Procedure

How to Create Scenario & Generate Traffic in NetSim:

Step 1: Go to Simulation -> New -> LTE

Step 2: Click & drop 2 eNB‟s, 1 MME and 4 UE‟s onto the Simulation Environment.

Connect the 2 eNB‟s with MME using Wired Link.

Right click on UE and select Properties. Change the Velocity to 100m/s in Global Properties

for all UE‟s

Accept default properties for eNB and MME

Page 44: Maharastra EXTC  NetSim Experiment  Manual

Step 3:

Application Properties:

To add application, drop the Application icon. Edit the Application properties as given in

table. All other properties are default.

Application Type CUSTOM

Source ID 5

Destination ID 6

Step 4:

Click on Run Simulation icon and set simulation time = 100s.

18.4 Output

Open Packet Animation:

Due to Mobility UEs can move from one cell to another. In the below figure, users can see

the handover packet flow in packet animation.

Page 45: Maharastra EXTC  NetSim Experiment  Manual

As shown in the above packet animation , UE E, UE D connected to eNB A and UE

F, UE G connected to eNB B

UE F is moving from eNB B to eNB A due to mobility

Then UEs send the LTE_Measurement_Report to eNB A, eNB B

The eNB B sends a LTE_Handover_Request message to the eNB A

The eNB A checks for resource availability and sends a

LTE_Handover_Request_Ack message to the eNB B

18.5 Inference

Firstly UE F is communicating with eNB B. Due to mobility UE F moves from one cell to

another. So Handover occurs. Now UE F starts communicating with eNB A.

Page 46: Maharastra EXTC  NetSim Experiment  Manual

Study how the Data Rate of a Wireless LAN 19.

(IEEE 802.11b) network varies as changing

Wireless Channel Characteristics .

19.1 Theory:

In most of the WLAN products on the market based on the IEEE 802.11b technology the

transmitter is designed as a Direct Sequence Spread Spectrum Phase Shift Keying (DSSS

PSK) modulator, which is capable of handling data rates of up to 11 Mbps. The system

implements various modulation modes for every transmission rate, which are Different

Binary Phase Shift Keying (DPSK) for 1 Mbps, Different Quaternary Phase Shift Keying

(DQPSK) for 2 Mbps and Complementary Code Keying (CCK) for 5.5 Mbps and 11 Mbps.

Large Scale Fading represents Receiver Signal Strength or path loss over a large area as a

function of distance. The statistics of large scale fading provides a way of computing

estimated signal power or path loss as a function of distance and modulation modes vary

depends on the Receiver Signal Strength.

19.2 Procedure:

Please navigate through the below given path to,

Go to Simulation New Internetworks

Sample Inputs:

Follow the steps given in the different samples to arrive at the objective.

In Sample 1,

Total no of APs (Access Points) used: 1

Total no of Wireless Nodes used: 1

Total no of Routers used: 1

Total no of Switches used: 1

Total no of Wired Nodes used: 1

Page 47: Maharastra EXTC  NetSim Experiment  Manual

The AP, Wireless Nodes, Router, Switch and Wired Nodes are interconnected as shown:

Also edit the following properties of Wireless Node E:

Wireless Node E Properties

X/Lat 365

Y/Lon 150

Interface_Wireless properties

RTS Threshold(bytes) 2347

Retry Limit(DataLink_Layer) 7

Rate _Adaptation true

Edit all link properties as shown:

Wireless Link Properties

Channel Characteristics Fading only

Path Loss Exponent 2.5

Fading Figure 1.0

Wired Link Properties

Uplink Speed (Mbps) 100

Downlink Speed (Mbps) 100

Uplink BER 0

Downlink BER 0

Page 48: Maharastra EXTC  NetSim Experiment  Manual

Also edit the following properties of Wired Node A:

Wired Node A Properties

TCP Disabled

Set the properties of Access Point as follows:

Access Point Properties

X/Lat 350

Y/Lon 150

Interface_Wireless properties

Buffer Size(MB) 5

RTS Threshold(bytes) 2347

Retry Limit 7

Click and drop the Application, set properties and run the simulation.

Application Properties

Application Type Custom

Source_Id 1

Destination_Id 5

Packet Size

Distribution Constant

Value (bytes) 1460

Packet Inter Arrival Time

Distribution Constant

Value (micro secs) 900

Page 49: Maharastra EXTC  NetSim Experiment  Manual

Simulation Time - 10 Sec

(Note: The Simulation Time can be selected only after the following two tasks,

Set the properties for all the devices and links.

Click on Run Simulation button.

Upon completion of the experiment, “Save” the metrics result for comparison . Save the

Experiment in any user defined location.

Sample 2: Change Wireless Channel Characteristics

Wireless Link Properties

Channel Characteristics Fading and Shadowing

Path Loss Exponent 2.5

Fading Figure 1.0

Sample 3: Change Wireless Channel Characteristics

Wireless Link Properties

Channel Characteristics Line of Sight

Path Loss Exponent 2.5

Sample 4: Change Wireless Channel Characteristics

Wireless Link Properties

Channel Characteristics No Path Loss

Page 50: Maharastra EXTC  NetSim Experiment  Manual

0

1

2

3

4

5

6

No Path Loss Line of Sight Fading Only Fading andShadowing

Thro

ugh

pu

t

Channel Characteristics

19.3 Output:

Channel

Characteristics

No Path Loss Line of Sight Fading Only Fading and

Shadowing

Throughput

(Mbps)

5.64 5.56 5.10 3.59

Comparison Chart:

19.4 Inference

*** All the above plots highly depend upon the placement of nodes in the simulation

environment. So, note that even if the placement is slightly different, the same set of values

will not be got but one would notice a similar trend.

In 802.11b, four data rates, 1 Mbps, 2 Mbps, 5.5 Mbps, and 11 Mbps, are supported. The rate

is decided based on the received power and the errors in the channel. Note a higher data rate

does not necessarily yield a higher throughput since packets may get errored. Only when the

channel conditions are good, does a higher data rate give a higher throughput. In a realistic

WLAN environment, the channel condition can vary due to pathloss, fading, and shadowing.

In NetSim to accommodate different channel conditions, rate adaptation is commonly

employed. The rate adaptation algorithms dynamically adjusts the modulation mode

Page 51: Maharastra EXTC  NetSim Experiment  Manual

and data rate to optimize performance when channel condition changes. So, when

NetSim detects that the number of errors in the channels are high, it automatically drops

down to a lower rate.

In addition, one must note that WLAN involves ACK packets after data transmission.. These

additional packet transmission lead to reduced Application throughput of 5.5 Mbps (at 1 – 20

mts range) even though the PHY layer data rate is 11 Mbps.

Page 52: Maharastra EXTC  NetSim Experiment  Manual

ETC 801 WIRELESS NETWORK

Introduction to GSM 20.

Refer: Study theory from NetSim Basic Menu “Cellular ” GSM

Analyze the scenario shown, where Node 1 21.

transmits data to Node 2, with no path loss and

obtain the theoretical throughput based on

IEEE 802.15.4 standard. Compare this with the

simulation result.

21.1.1 Introduction:

IEEE Standard 802.15.4 defines the protocol and compatible interconnections for data

communication devices using low-data-rate, low-power, and low-complexity short-range

radio frequency (RF) transmissions in a wireless personal area network (WPAN). In Wireless

sensor network IEEE 802.15.4 standard is used in MAC and PHY layers.

IEEE 802.15.4 PHYs provide the capability to perform CCA in its CSMA-CA mechanism.

The PHYs require at least one of the following three CCA methods: Energy Detection over a

certain threshold, detection of a signal with IEEE 802.15.4 characteristics or a combination

of these methods.

Page 53: Maharastra EXTC  NetSim Experiment  Manual

21.1.2 Theory:

A packet transmission begins with a random backoff (in number of slots, each slot of 20

duration) which is sampled uniformly from 0 to and followed by a

CCA.

CCA failure starts a new backoff process with the backoff exponent raised by one, i.e., to

macminBE+1, provided it is lesser than the maximum backoff value given by

macmaxBE.

Maximum number of successive CCA failures for the same packet is governed by

macMaxCSMABackoffs, exceeding which the packet is discarded at the MAC layer.

A successful CCA is followed by the radio turnaround time and packet transmission.

If the receiver successfully receives the packet i.e., without any collision or corruption

due to PHY layer noise, the receiver sends an ACK after the radio turnaround time.

A failed packet reception causes no ACK generation.

The transmitter infers that the packet has failed after waiting for macAckWaitDuration

and retransmits the packet for a maximum of aMaxFrameRetries times before discarding

it at the MAC layer.

Note: In NetSim the radio turnaround time after a CCA success is not considered.

21.1.3 Procedure

How to Create Scenario: In NetSim, Select “Simulation New ZigbeeNetworks”

Create the scenario as shown:

Page 54: Maharastra EXTC  NetSim Experiment  Manual

Set the properties as shown below:

Node Properties:

Node Properties Zigbee Node B

Global Properties

X_Coordinate 15

Y_Coordinate 20

Interface1_Zigbee : Data Link Layer

AckRequest Enable

MaximumFrameRetries 7

Node Properties Zigbee Node C

Global Properties

X_Coordinate 25

Y_Coordinate 20

Interface1_Zigbee : Data Link Layer

AckRequest Enable

MaximumFrameRetries 7

PAN Coordinator Properties:

Sink Node Properties Values

Global Properties

X_Coordinate 20

Y_Coordinate 20

Interface1_Zigbee : Data Link Layer

Beacon Mode Disable

Page 55: Maharastra EXTC  NetSim Experiment  Manual

Environment Properties:

Environment Properties Values

Channel Characteristics No Path Loss

Click and drop Application and edit the following properties:

Application Properties

Application Type Custom

Source_Id 2 (Zigbee Node B)

Destination_Id 3 (Zigbee Node C)

Packet_Size

Distribution Constant

Value(Bytes) 70

Inter_Arrival_time

Distribution Constant

Value(micro sec) 4000

(Note: If the size of the packet size at the Physical layer is greater than 127 bytes, the packet

gets fragmented. Taking into account the various overheads added at different layers (which

are mentioned below), the packet size at the application layer should be less than 80 bytes.)

Simulation Time: 100 Sec

Throughput obtained from the simulation is100.408kbps (0.100408 Mbps)

Note: This throughput is obtained when the nodes are placed at the closest possible distance

from the PAN coordinator. As the distance is increased, the throughput would reduce.

Theoretical Analysis:

We have set the Application layer payload as 70 bytes in the Node1 properties and when the

packet reaches the physical layer various other headers gets added like

Page 56: Maharastra EXTC  NetSim Experiment  Manual

App layer Payload 70 bytes

Transport Layer Header 8 bytes

Network Layer Header (IP + DSR) 28 bytes

MAC Header 5 bytes

PHY Header 6 bytes

Packet Size 117 bytes

In simulation, by default NetSim uses Unslotted CSMA/CA and so a packet transmission

happens after random backoff, CCA and turn-around-time and is followed by turn-around-

time and ACK packet and each of them occupies specific time set by the IEEE 802.15.4

standard as per the timing diagram shown below.

From IEEE standard, each slot has 20 Symbols in it and each symbol takes 16µs for

transmission:

Symbol Time 16 µs

Slot Time 20 * 0.32 ms

Random Backoff Average 3.5 * 1.12 ms

CCA 0.4 * 0.l28 ms

3.5

Slots

0.6

Slots

0.6

Slots

0.6

Slots

0.4

Slots

CCA Turn around

Time

Random

backoffAvg

[0, 7]

117 bytes

11.7 Slots

Packet Turn

around

Time

Ack

Source Node Destination

Node

Page 57: Maharastra EXTC  NetSim Experiment  Manual

Turn-around-Time 0.6 * 0.192 ms

Packet Transmission Time 11.7 * 3.744 ms

Turn-around-Time 0.6 * 0.192 ms

ACK Packet Time 0.6 * 0.192 ms

Total Time 17.4 * 5.568ms

21.1.4 Inference:

Throughput from theoretical analysis matches the results of NetSim‟s discrete event

simulation.

(Note: The slight difference in throughput is due to fact that the average of random numbers

generated for backoff need not be exactly 3.5 as the simulation is run for short time and also

in Network layer DSR protocol is running, so route setup process will take some time.)

As we go on increasing the simulation time, the throughput value obtained from simulation

approaches the theoretical value as can be seen from the table below:

Throughput from simulation 100.408 kbps

Throughput from analysis 100.574 kbps

Simulation Time (sec) Throughput (kbps)

10 99.680

50 100.486

100 100.408

200 100.486

Page 58: Maharastra EXTC  NetSim Experiment  Manual

Mobility Models in Wi-MAX (IEEE 802.16e/m) 22.

Network

22.1 Theory:

Random walk: In this mobility model, a mobile node moves from its current location to a

new location by randomly choosing a direction and speed in which to travel. Each movement

in the Random Walk Mobility Model occurs in either a constant time interval „t „or a constant

traveled ‟ d „distance, at the end of which a new direction and speed are calculated.

Random way point: The Random Way Point Mobility Model includes pauses between

changes in direction and/or speed. A Mobile node begins by staying in one location for a

certain period of time (i.e pause). Once this time expires, the mobile node chooses a random

destination in the simulation area. The mobile node then travels toward the newly chosen

destination at the selected speed. Upon arrival, the mobile node pauses for a specified period

of time starting the process again.

22.2 Procedure:

Sample 1(Random Walk):

Step 1:

In NetSim, Select “Simulation New Advanced Wireless Networks Wi-Max”.

Page 59: Maharastra EXTC  NetSim Experiment  Manual

Step 2:

Drop 1 Base Station and 2 Wi-Max Subscriber as shown below:

Step 3:

BS Properties BS A

Global Properties

X_Coordinate 200

Y_Coordinate 50

Step 4:

Subscriber Node Properties Subscriber Node B Subscriber Node C

Global Properties

X_Coordinate 150 250

Y_Coordinate 100 100

Page 60: Maharastra EXTC  NetSim Experiment  Manual

Subscriber Node Properties: Right click on the Subscriber Node and set the Mobility

Model as RANDOM_WALK and Velocity(m/s) as 10 in all the Subscriber Nodes.

Step 4: Select the Application Button and click on the gap between the Grid Environment

and the ribbon. Now right click on Application and select Properties as shown below:

Application Properties

Application Type Custom

Source ID 2 (Subscriber Node B)

Destination ID 3 (Subscriber Node C)

Packet Size

Distribution Constant

Value(Bytes) 1460

Inter Arrival Time

Distribution Constant

Value(µs) 2336

Page 61: Maharastra EXTC  NetSim Experiment  Manual

Step 5:

Simulation Time - 10 Sec

After completion of the experiment, “Save” the experiment for future analysis of results.

Sample 1.b:

Open Sample 1.a, Right click on the Subscriber Node and set the Mobility Model as

RANDOM_WALK and Velocity(m/s) as 30 in all the Subscriber Nodes.

Sample 1.c:

Open Sample 1.b, Right click on the Subscriber Node and set the Mobility Model as

RANDOM_WALK and Velocity(m/s) as 60 in all the Subscriber Nodes.

Sample 1.d:

Open Sample 1.c, Right click on the Subscriber Node and set the Mobility Model as

RANDOM_WALK and Velocity(m/s) as 90 in all the Subscriber Nodes.

Sample 2(Random Way Point):

Sample 2.a:

Open Sample 1a, Right click on the Subscriber Node and set the Mobility Model as

RANDOM_WAY_POINT and Velocity(m/s) as 10 in all the Subscriber Nodes.

The remaining properties are same as Sample 1a.

Sample 2.b:

Open Sample 2.a, Right click on the Subscriber Node and set the Mobility Model as

RANDOM_WAY_POINT and Velocity(m/s) as 30 in all the Subscriber Nodes.

Sample 2.c:

Open Sample 2.b, Right click on the Subscriber Node and set the Mobility Model as

RANDOM_WAY_POINT and Velocity(m/s) as 60 in all the Subscriber Nodes.

Page 62: Maharastra EXTC  NetSim Experiment  Manual

Sample 2.d:

Open Sample 2.c, Right click on the Subscriber Node and set the Mobility Model as

RANDOM_WAY_POINT and Velocity(m/s) as 90 in all the Subscriber Nodes.

22.3 Output

Velocity

(m/s)

Random Walk Random Way Point

Throughput

(Mbps)

Delay

(Second)

Throughput

(Mbps)

Delay

(Second)

10

30

60

90

2.62

2.57

2.53

2.30

1.78

1.89

1.85

1.96

2.57

2.49

2.37

2.29

1.78

1.99

2.08

2.03

22.4 Inference

As the mobility model is changed (Random Walk Random Waypoint) the throughput of

the network decreases because the relative change in location of the devices increases.

Throughput of Random Waypoint is less compared to Random walk as the relative velocity

among the nodes is zero only during pause time.

The packet delivery ratio decreases as collisions are higher for higher relative velocity

leading to lower number of packets successfully reaching the destination.

Page 63: Maharastra EXTC  NetSim Experiment  Manual

Study the SuperFrame Structure and analyze 23.

the effect of SuperFrame order on throughput.

23.1 Introduction:

Beacon frame is one of the management frames in IEEE 802.15.4 based WSN and contains

all the information about the network.

A coordinator in a PAN can optionally bound its channel time using a SuperFrame structure

which is bound by beacon frames and can have an active portion and an inactive portion. The

coordinator enters a low-power (sleep) mode during the inactive portion.

The structure of this SuperFrame is described by the values of macBeaconOrder and

macSuperframeOrder. The MAC PIB attribute macBeaconOrder, describes the interval at

which the coordinator shall transmit its beacon frames. The value of macBeaconOrder, BO,

and the beacon interval, BI, are related as follows:

For 0 ≤ BO ≤ 14, BI = aBaseSuperframeDuration * 2BO

symbols.

If BO = 15, the coordinator shall not transmit beacon frames except when requested to do so,

such as on receipt of a beacon request command. The value of macSuperframeOrder, SO

shall be ignored if BO = 15. An example of a SuperFrame structure is shown in following

Figure.

Page 64: Maharastra EXTC  NetSim Experiment  Manual

Fig: An example of the Super Frame structure

Theoretical Analysis:

From the above SuperFrame structure,

If SuperFrame Order (SO) is same as Beacon Order (BO) then there will be no inactive

period and the entire SuperFrame can be used for packet transmissions.

If BO=10, SO=9 half of the SuperFrame is inactive and so only half of SuperFrame duration

is available for packet transmission. If BO=10, SO=8 then (3/4)th of the SuperFrame is

inactive and so nodes have only (1/4)th

of the SuperFrame time for transmitting packets and

so we expect throughput to approximately drop by half of the throughput obtained when

SO=9.

Percentage of inactive and active periods in SuperFrame for different SuperFrame Orders is

given below:

Beacon

Order (BO)

SuperFrame

Order (SO)

Active part

ofSuperFrame(%

)

Inactive part of

SuperFrame (%)

Throughput

estimated (%)

10 10 100 0 > 200% of T

10 9 50 50 Say T = 20.18 (Got from simulation)

10 8 25 75 50 % T

10 7 12.5 87.5 25 % T

10 6 6.25 93.75 12.5 % of T

10 5 3.125 96.875 6.25 % of T

10 4 1.5625 98.4375 3.12% of T

10 3 0.78125 99.21875 1.56 % of T

Page 65: Maharastra EXTC  NetSim Experiment  Manual

We expect throughput to vary in the active part of the SuperFrame as sensors can transmit a

packet only in the active portion.

Simulation:

How to Create Scenario & Generate Traffic:

In NetSim, Go to “Simulation New Wireless Sensor Networks”

In grid settings, enter side length as 100 m and select sensor placement strategy as Via click

& drop

Click & drop one Sensor Node, Sink Node and Agent onto the Simulation Environment:

Sensor Properties: Change the following property for Sensor.

Sensor Properties Values

Velocity(m/s) 0

Interface1_Zigbee: Sensor

Sensor Interval (ms) 3

Page 66: Maharastra EXTC  NetSim Experiment  Manual

Sink Node Properties: Change the following properties for PAN Coordinator.

Sink Node Properties Values

Interface1_Zigbee: Data link Layer

Beacon Mode Enable

Beacon Order 10

Super frame Order 10

Simulation Time -30 Sec.

(Note: The Simulation Time can be selected only after doing the following two tasks,

Set the properties of Node, PAN Coordinator & Environment.

Click on Run Simulation and save the experiment)

Sample 2 and so on: Vary the Super Frame Order for every sample (SuperFrame order = 9

for sample 2, and…, 3 for sample 8).

The following are the throughputs obtained from simulation for different SuperFrame Orders.

SuperFrame

Order

Throughput

(Kbps)

10 40.00

9 20.23

8 10.08

7 5.04

6 2.50

5 1.24

4 0.60

3 0.28

Page 67: Maharastra EXTC  NetSim Experiment  Manual

Note: To obtain throughput from simulation, payload transmitted values will be obtained

from Network statistics and calculated using following formula:

Comparison Chart:

*** All the above plots highly depend upon the placement of Sensor in the simulation

environment. So, note that even if the placement is slightly different the same set of values

will not be got but one would notice a similar trend.

23.1.1 Inference:

From the comparison chart both the simulation and theoretical throughputs match except for

the case with no inactive period. A sensor will be idle if the last packet in its queue is

transmitted. If a packet is generated in inactive period then the packet has to wait in the

queue till the next SuperFrame so sensor has packets waiting in its queue and so it cannot be

idle in the next SuperFrame, but if there is no inactive period then there might be no packets

waiting in the queue and so sensor can be idle resulting in lesser throughput.

0

5

10

15

20

25

30

35

40

45

10 9 8 7 6 5 4 3

Thro

ugh

pu

t (k

bp

s)

Superframe Order

Simulated

Theoritical

Page 68: Maharastra EXTC  NetSim Experiment  Manual

ETC 803 INTERNET AND VOICE COMMUNICATION

TCP/IP Networking model 24. Refer: Study theory from NetSim “Basic Menu Internetwork TCPIntroduction”

Internet Layering and ISO Model 25. Refer: Study theory from NetSim “Basic Menu Introduction Network Architecture

Layering and OSI Model”

Understand IP forwarding within a LAN and 26.

across a router Note: NetSim Standard Version is required to run this experiment

26.1.1 Theory:

Nodes in network need MAC Addresses in addition to IP address for communicating with

other nodes. In this experiment we will see how IP-forwarding is done when a node wants to

send data within a subnet and also when the destination node is outside the subnet.

26.2 Procedure

Step 1:

Go to Simulation New Internetworks

Step 2:

Click & drop Wired Nodes, Switches

and Router onto the Simulation Environment as shown

and link them.

Page 69: Maharastra EXTC  NetSim Experiment  Manual

Node properties: Disable TCP in all nodes in Transport layer as follows:

Step 3: Create the Sample as follows

Sample 1:

To run the simulation, drop the Application icon and set Application type CUSTOM and the

Source_Id and Destination_Id as 1 and 2 respectively

Enabling the packet trace:

Click Packet Trace icon in the tool bar. This is used to log the packet details.

Check “All the Attributes” button for Common Attributes, TCP and WLAN.

And Click on Ok button. Once the simulation is completed, the file gets stored in the

location specified.

Page 70: Maharastra EXTC  NetSim Experiment  Manual

Step 4:

Simulation Time- 10 Seconds

Note: The Simulation Time can be selected only after doing the following two tasks,

Set the properties of Nodes

Then click on the Run Simulation icon:

After clicking on Run Simulation, edit IP and ARP Configuration tab by setting Static ARP

as Disable. Click on OK button to simulate.

26.3 Output - I

Open Packet Trace for performing Packet Trace analysis

PACKET TRACE Analysis

Page 71: Maharastra EXTC  NetSim Experiment  Manual

26.4 Inference - I

Intra-LAN-IP-forwarding:

ARP PROTOCOL- WORKING

A Brief Explanation:

NODE-1 broadcasts ARP_Request which is then broadcasted by SWITCH-4. NODE -2

sends the ARP_Reply to NODE-1 via SWITCH-4. After this step, data is transmitted from

NODE-1 to NODE-2. Notice the DESTINATION_ID column for ARP_Request type

packets.

Step 5: Follow all the steps till Step 2 and perform the following sample:

Sample 2:

To run the simulation, drop the Application icon and set the Source_Id and Destination_Id as

1 and 3 respectively.

Source Switch

ARP REQUEST

Destination

ARP Response

ARP REQUEST

ARP Response

Page 72: Maharastra EXTC  NetSim Experiment  Manual

Enabling the packet trace:

Click Packet Trace icon in the tool bar. This is used to log the packet details.

Give a file name and check “All the Attributes” button for Common Attributes, TCP

and WLAN.

And Click on Ok button. Once the simulation is completed, the file gets stored in the

specified location.

Step 6:

Simulation Time- 10 Seconds

Note: The Simulation Time can be selected only after doing the following two tasks,

Set the properties of Nodes

Then click on the Run Simulation icon:

After clicking on Run Simulation, edit IP and ARP Configuration tab by setting Static ARP

as Disable. Click on OK button to simulate.

Page 73: Maharastra EXTC  NetSim Experiment  Manual

26.5 Output - II

PACKET TRACE Analysis

Across-Router-IP-forwarding:

Data Packet

ARP request for

Destination’s MAC

address

ARP

Response

Source

Default Gateway

ARP request for

Default Gateway’s

MAC address

ARP response for

Default Gateway’s

MAC address

Source

Default Gateway

Destination

STEP-1 STEP-2

Data Packet

Page 74: Maharastra EXTC  NetSim Experiment  Manual

26.6 Inference -II

NODE-1 transmits ARP_Request which is further broadcasted by SWITCH-4. ROUTER-6

sends ARP_Reply to NODE-1 which goes through SWITCH-4. Then NODE-1 starts to send

data to NODE-3.

If the router has the address of NODE-3 in its routing table, ARP protocol ends here and data

transfer starts that is PACKET_ID 1 is being sent from NODE-1 to NODE-3. In other case,

Router sends ARP_Request to appropriate subnet and after getting the MAC ADDRESS of

the NODE-3, it forwards the packet which it has received from NODE-1.

When a node has to send data to a node with known IP address but unknown MAC address,

it sends an ARP request. If destination is in same subnet as the source (found through subnet

mask) then it sends the ARP (broadcast ARP message) request. Otherwise it forwards it to

default gateway. Former case happens in case of intra-LAN communication. The destination

node sends an ARP response which is then forwarded by the switch to the initial node. Then

data transmission starts.

In latter case, a totally different approach is followed. Source sends the ARP request to the

default gateway and gets back the MAC address of default gateway. (If it knows which router

to send then it sends ARP request to the corresponding router and not to Default gateway)

When source sends data to default gateway (a router in this case), the router broadcasts ARP

request for the destined IP address in the appropriate subnet. On getting the ARP response

from destination, router then sends the data packet to destination node.

PART 2: - Changing default Gateway

Do Sample 2 in PART 1 with the difference that in the properties of NODE-1, change the

default gateway to some other value, for ex. “192.168.2.76” and click on Simulate button.

You will get error. Because NODE-1 will check the IP address of NODE-3 and then realize

that it isn‟t in the same subnet. So it will forward it to default gateway. Since the default

gateway‟s address doesn‟t exist in the network, error occurs.

Page 75: Maharastra EXTC  NetSim Experiment  Manual

Dynamic Host Configuration Protocol 27.

Programming Guidelines

This section guides the user to link his/her own code for Dynamic Host Configuration

Protocol to NetSim.

Pre - Conditions

The user program should read the input from text file named „Input‟ with extension txt.

The user program after executing the concept should write the required output to a file named

„Output’ with extension txt.

Note: The temporary directory is navigated through the following step.

Run Type "%temp%" NetSim "Input.txt" and "Output.txt"

General Program Flow

The program begins with the Reading of the Inputs from the input file Input.txt.

Executing the required concept and

The results of the program should be written into the output file Output.txt.

Input File Format Output File Format

Number_of_Clients = 4

Start_Address = 192.168.0.105

End_Address = 192.168.0.109

Mask = 255.255.255.0

DHCP_DISCOVER>

Node1>Node2>

Node1>Node3>

Node1>Node4>

Node1>Server

DHCP_OFFER>

Server>Node1

DHCP_REQUEST>

Node1>Server

DHCP_ACK>

Server>192.168.0.105

DHCP_DISCOVER>

Node2>Node1>

Node2>Node3>

Node2>Node4>

Node2>Server

Page 76: Maharastra EXTC  NetSim Experiment  Manual

DHCP_OFFER>

Server>Node2

DHCP_REQUEST>

Node2>Server

DHCP_ACK>

Server>192.168.0.106

DHCP_DISCOVER>

Node3>Node1>

Node3>Node2>

Node3>Node4>

Node3>Server

DHCP_OFFER>

Server>Node3

DHCP_REQUEST>

Node3>Server

DHCP_ACK>

Server>192.168.0.107

DHCP_DISCOVER>

Node4>Node1>

Node4>Node2>

Node4>Node3>

Node4>Server

DHCP_OFFER>

Server>Node4

DHCP_REQUEST>

Node4>Server

DHCP_ACK>

Server>192.168.0.108

Interface Source Code

Interface Source code written in C is given using this the user can write only the Dynamic

Host Configuration Protocol inside the function fnDHCPServer() and fnDHCPClient() using

the variables already declared.

To view the interface source code, go to

NetSim Installation path / src / Programming / DHCP.c

To find NetSim‟s Installation path right click NetSim icon and select

Open file location in Windows 7

Page 77: Maharastra EXTC  NetSim Experiment  Manual

Open file location in Windows Vista

Properties find target in Windows XP.

Sample Scenarios:

Objective - Find the Shortest Path using Dynamic Host Configuration Protocol.

How to Proceed? - The objective can be executed in NetSim by using the programming

exercise available. In the Programming menu selectDynamic Host Configuration

Protocol.

Sample Input -Follow the below given steps,

Select number of clients.

Set the Start Address and the End Address

Click on Run button to execute.

Output - The Output that is obtained is given below,

Page 78: Maharastra EXTC  NetSim Experiment  Manual

Configure and analyze the TCP versus UDP 28.

response Time With HTTP Application Note: NetSim Standard Version is required to run this experiment

28.1 Theory

TCP provides connection-oriented service at the transport layer, and UDP provides

connectionless service. As a result, a data exchange using TCP can take longer than the same

exchange using UDP. TCP implementations require that the TCP source and destination

perform a three-way handshake in order to set up the connection prior to sending data, and a

four-way handshake when tearing down the connection. In addition, all data must be

acknowledged by the destination when it is received. UDP sources, on the other hand, do not

set up connections and so save the overhead in terms of delay and bandwidth usage. UDP is

often used when small amounts of data must be sent, for example, when doing credit card

verification. If large amounts of data are sent, however, the extra TCP overhead may be

negligible in comparison to the entire transaction completion time

28.2 Part-A – TCP

Procedure: Sample 1

Step 1:

Go to Simulation New Internetworks

Step 2:

Click & drop 2 Wired Nodes and 1

Router on the Simulation Environment

as shown and link them.

Page 79: Maharastra EXTC  NetSim Experiment  Manual

Application Properties

Application Type HTTP

Source_Id 2(Wired Node D)

Destination_Id 3(Wired Node C)

Page Property

Distribution Constant

Page Count 10

Page Size (bytes) 1000

Inter Arrival Time

Distribution Constant

Value ( secs) 1

Step 3:

Enable Packet Trace in Ribbon

Step 4:

Simulation Time - 10 sec

(Note: The Simulation Time can be selected only after the following two tasks,

Enable Packet Trace

Click on Run Simulation button.

After completion of the experiment, “Save” the experiment for future analysis of results.

28.3 Part-B – UDP

Procedure: Sample 2:

Open Sample 1 and Disable TCP in Transport Layer in both Wired Nodes and

Router

Simulation Time - 10 sec

(Note: The Simulation Time can be selected only after the following two tasks,

Page 80: Maharastra EXTC  NetSim Experiment  Manual

Enable Packet Trace

Click on Run Simulation button)

28.4 Output:

Open Packet Trace from performance metrics window

Apply filter option from Excel sheet, filter PACKET TYPE column: Select only HTTP

TCP Packet Trace

TCP Response Time: 1000385.28 - 1000054.56 = 330.72

UDP Packet Trace

UDP Response Time: 1000321.12-1000000.96=320.16

Page 81: Maharastra EXTC  NetSim Experiment  Manual

Response Time

( micro. sec)

TCP 330.72

UDP 320.16

28.4.1 Inference:

Response time of TCP is greater than UDP. Since TCP performs three way handshake

mechanisms, for each packet it has to wait for an acknowledgement. But in case of UDP,

there is no acknowledgement. Hence compared to TCP, UDP has less Response

Page 82: Maharastra EXTC  NetSim Experiment  Manual

Simulation of different types of internet 29.

traffic such as FTP, TELNET over a network

and analyzing the throughput

29.1 Theory:

FTP is File Transfer Protocol that transfers the files from source to destination. It is an

application layer protocol. The file transfer takes place over TCP.

TELNET is Terminal Network Protocol that is used to access the data in the remote machine.

It is also an Application layer protocol. It establishes connection to the remote machine over

TCP.

29.2 Procedure:

29.2.1 How to Create Scenario & Generate Traffic:

Create Scenario: “Simulation New Internetworks”.

29.2.2 Sample Inputs:

FTP, Database, Voice, HTTP, Email, Peer to Peer and Video are the traffic types available as

options in NetSim. To model other applications the “Custom” option is available. TELNET

application has been modeled in NetSim by using custom traffic type. Packet Size and Packet

Inter Arrival Time for TELNET application is shown below:

Packet Size

Distribution Constant

Packet Size (Bytes) 1460

Packet Inter Arrival Time

Distribution Constant

Packet Inter Arrival Time (µs) 1500

Page 83: Maharastra EXTC  NetSim Experiment  Manual

Fig 1: The Network Scenario

In this experiment, 8 Wired Nodes and 3 Routers need to be clicked & dropped onto the

Simulation environment. Wired Nodes A, B and C are connected to Router I. Wired Nodes

E, F, G and H are connected to Router K. Wired Node D is connected to Router J. Router I

and Router K are connected to Router J. The network scenario is shown in above fig 1.

Then follow these steps:

Sample 1: FTP Application from Wired Node D to Wired Node E.

Sample 2: FTP Application from Wired Node D to Wired Node E. TELNET Application

from Wired Node A to Wired Node F.

Sample 3: FTP Application from Wired Node D to Wired Node E. TELNET Application

from Wired Node A to Wired Node F. TELNET Application from Wired Node B to Wired

Node G.

TELNET

FTP

Page 84: Maharastra EXTC  NetSim Experiment  Manual

Sample 4: FTP Application from Wired Node D to Wired Node E. TELNET Application

from Wired Node A to Wired Node F. TELNET Application from Wired Node B to Wired

Node G. TELNET Application from Wired Node C to Wired Node H.

Note: Select “custom” for “TELNET” application

Inputs for the Sample experiment are given below:

Set the following properties for all wired links.

Wired Node Properties:

Set the following properties for Wired Node D if application type is FTP and destination is

Wired Node E. Set the following properties for Wired Node A if application type is TELNET

and destination is Wired Node F.

Node Properties Wired Node D Wired Node A

Transport Layer Properties

TCP Enable Enable

Application Properties: (set the application property as per screenshot)

Application Type FTP Custom(for TELNET)

Source ID Wired Node D Wired Node A

Destination ID Wired Node E Wired Node F

Size

Distribution Constant Constant

Size (Bytes) 10000000 1460

Inter Arrival Time

Distribution Constant Constant

Inter Arrival Time 10 sec 1500 (µs)

Router Properties: Accept default properties for the Router.

Page 85: Maharastra EXTC  NetSim Experiment  Manual

Wired Link Properties: Set the following properties for all Wired Links.

Link Properties All Wired Links

Uplink Speed (Mbps) 1

Downlink Speed (Mbps) 1

Uplink BER No Error

Downlink BER No Error

Simulation Time - 100 Sec

Upon completion of the experiment “Save” the experiments for comparisons which is carried

out in the “Analytics” section and export to .csv to save the results.

29.2.3 Output:

Open the Excel Sheet and note down the various throughputs as shown in the table below.

These throughput values are available under application metrics in the metrics screen of

NetSim.

Experiment

Number

Source Destination Application Throughput

1 Wired Node D Wired Node E FTP 0.842595

2 Wired Node D Wired Node E FTP 0.662840

2 Wired Node A Wired Node F TELNET 0.257427

3 Wired Node D Wired Node E FTP 0.557720

3 Wired Node A Wired Node F TELNET 0.175550

3 Wired Node B Wired Node G TELNET 0.189917

4 Wired Node D Wired Node E FTP 0.486706

4 Wired Node A Wired Node F TELNET 0.146818

4 Wired Node B Wired Node G TELNET 0.142262

4 Wired Node C Wired Node H TELNET 0.144949

Page 86: Maharastra EXTC  NetSim Experiment  Manual

29.2.3.1 Graph I

29.2.3.2 Graph II

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1 FTP 1 FTP + 1 TELNET 1 FTP + 2 TELNET 1 FTP + 3 TELNET

FTP

Th

rou

ghp

ut(

Mb

ps)

FTP Throughput

0

0.05

0.1

0.15

0.2

0.25

0.3

1 FTP + 1 TELNET 1 FTP + 2 TELNET 1 FTP + 3 TELNET

TELN

ET T

hro

ugh

pu

t(M

bp

s)

TELNET Throughput of Wired Node 1

Page 87: Maharastra EXTC  NetSim Experiment  Manual

29.2.4 Inference

From Graph I it can be inferred that FTP throughput decreases as the number of

transmitting nodes of TELNET application increases. Wired link 5 is used for FTP traffic. All

TELNET applications in this experiment also used Wired Link 5. Hence as the TELNET

traffic over wired link 5 increases the FTP throughput decreases.

From Graph II it can be inferred that TELNET throughput of Wired Node 1 decreases as

the number of transmitting nodes of TELNET application increases. TELNET traffic of wired

node 1 flows through wired link 5. Other TELNET applications also used the wired link 5.

Hence as the overall TELNET traffic over wired link 5 increases, the TELNET throughput

of Wired Node 1 decreases.

Page 88: Maharastra EXTC  NetSim Experiment  Manual

User Datagram Protocol (UDP) and Header 30.

Fields

Refer: Study theory from NetSim “Basic Menu Internetwork UDP

Introduction”

Refer: Study theory from NetSim “Basic Menu Internetwork UDP UDP

Protocol Header Format”

Page 89: Maharastra EXTC  NetSim Experiment  Manual

Understand the working of “Connection 31.

Establishment” in TCP using NetSim. Note: NetSim Standard Version is required to run this Experiment.

31.1.1 Theory

When two processes wish to communicate, their TCP‟s must first establish a connection i.e.

initialize the status information on each side. Since connections must be established between

unreliable hosts and over the unreliable internet communication system, a “three-way

handshake” with clock based sequence numbers is the procedure used to establish a

Connection. This procedure normally is initiated by one TCP and responded by another TCP.

The procedure also works if two TCPs simultaneously initiate the procedure. When

simultaneous attempt occurs, each TCP receives a “SYN” segment which carries no

acknowledgement after it has sent a “SYN”.

The simplest three-way handshake is shown in the following figure.

TCP A TCP B

1. CLOSED LISTEN

2. SYN-SENT <A: SEQ=100><CTL=SYN> SYN-RECEIVED

3. ESTABLISHED ` <B: SEQ=300><ACK=101><CTL=SYN, ACK> SYN-RECEIVED

4. ESTABLISHED <A: SEQ=101><ACK=301><CTL=ACK> ESTABLISHED

5. ESTABLISHED <A: SEQ=101><ACK=301><CTL=ACK><DATA> ESTABLISHED

Fig: Basic 3-Way Handshake for Connection Synchronization

Explanation:

The above figure should be interpreted in the following way. Each line is numbered for

reference purposes. Right arrows () indicates the departure of a TCP Segment from TCP A

to TCP B, or arrival of a segment at B from A. Left arrows ( ) indicates the reverse.TCP

states represent the state AFTER the departure or arrival of the segment (whose contents are

shown in the center of each line).Segment contents are shown in abbreviated form, with

sequence number, control flags, and ACK field. In line2 of the above figure, TCP A begins

by sending a SYN segment indicating that it will use sequence numbers starting with

Page 90: Maharastra EXTC  NetSim Experiment  Manual

sequence number 100. In line 3, TCP B sends a SYN and acknowledges the SYN it received

from TCP A. Note that the acknowledgment field indicates TCP B is now expecting to hear

sequence 101, acknowledging the SYN which occupied sequence 100. At line 4, TCP A

responds with an empty segment containing an ACK for TCP B's SYN; and in line 5, TCP A

sends some data.

31.1.2 Procedure

Step1:

Go to Simulation New Internetworks

Step2:

Click & drop Wired Nodes and Router onto the Simulation Environment and link them as

shown below.

Step3:

To run the simulation, drop the Application icon and change the Application_type to FTP.

The Source_Id is 1 and Destination_Id is 2.

Page 91: Maharastra EXTC  NetSim Experiment  Manual

Router Properties: Accept default properties for Router.

Enabling the packet trace:

Click Packet Trace icon in the tool bar. This is used to log the packet details.

Select the required attributes and click OK. Once the simulation is completed, the file

gets stored in the location specified.

Note: Make sure that after enabling the packet trace you select the TCP option in the

Internetworks and then select the required attributes.

Simulation Time - 10 sec

After clicking on “Run Simulation”, edit IP and ARP Configuration tab by setting Static

ARP as Disable.

Page 92: Maharastra EXTC  NetSim Experiment  Manual

31.2 Output

The following results will be obtained:

Click on Open Packet Trace for performing

Packet Trace analysis

Fig: 3-way Handshake using packet trace.

31.3 Inference

In MS Excel go to DATA and select FILTER option to view only the desired rows and

columns as shown in the figure

Line 1, 2, 3 and 4 of the above table are ARP related packets and not of interest to us in this

experiment.

In line 9 of the above figure we can see that NODE-1 is sending a control packet of type

TCP_SYN requesting the connection with the NODE-2, and this control packet is first sent to

Page 93: Maharastra EXTC  NetSim Experiment  Manual

the ROUTER-3 (receiver ID). In line 10, the ROUTER-3 is sending the TCP_SYN packet

that has been received from NODE-1 to the NODE-2. In line 11, NODE-2 is sending the

control packet of type TCP_SYN_ACK to NODE-1, and this control packet is first sent to

the ROUTER-3. This TCP_SYN_ACK is the ACK packet for the TCP_SYN packet. In line

12, ROUTER-3 is sending the TCP_SYN_ACK, (received from NODE-2) to the NODE-1.

In line 13, NODE-1 is sending the TCP_ACK to NODE-2 via ROUTER-3 making the

CONNECTION_STATE as TCP_ESTABLISHED.

Once the connection is established, we see that a packet type of type “FTP” is sent from the

NODE-1 to the NODE-2 in line 14.

Page 94: Maharastra EXTC  NetSim Experiment  Manual

Simulating a three node point-to-point 32.

network and applying relevant applications

over TCP and UDP

32.1 Objective:

Simulate a three node point-to-point network with the links connected as follows:

n0 – n2, n1 – n2 and n2 – n3. Apply TCP agent between n0-n3 and UDP between n1-n3.

Apply relevant applications over TCP and UDP agents changing the parameter and determine

the number of packets sent by TCP / UDP. (n0, n1 and n3 are nodes and n2 is router.)

32.2 Theory:

TCP:

TCP recovers data that is damaged, lost, duplicated, or delivered out of order by the internet

communication system. This is achieved by assigning a sequence number to each octet

transmitted, and requiring a positive acknowledgment (ACK) from the receiving TCP. If the

ACK is not received within a timeout interval, the data is retransmitted. At the receiver side

sequence number is used to eliminate the duplicates as well as to order the segments in

correct order since there is a chance of “out of order” reception. Therefore, in TCP no

transmission errors will affect the correct delivery of data.

UDP:

UDP uses a simple transmission model with a minimum of protocol mechanism. It has no

handshaking dialogues, and thus exposes any unreliability of the underlying network protocol

to the user's program. As this is normally IP over unreliable media, there is no guarantee of

delivery, ordering or duplicate protection.

32.3 Procedure:

To Create Scenario, goto Simulation New Internetworks.

Click & drop Router, Wired Nodes and Application onto the Simulation Environment

from tool bar as shown below.

Page 95: Maharastra EXTC  NetSim Experiment  Manual

32.4 Sample Inputs:

Sample 1

Set the properties for the devices and links as shown below:

Wired Node Properties:

Wired Node Properties Wired Node B Wired Node C

Transport Layer Properties

TCP Enable Disable

UDP Disable Enable

Application Properties:

Application Type Custom Custom

Source ID 2(Wired Node B) 3(Wired Node C)

Destination ID 4(Wired Node D) 4(Wired Node D)

Packet Size

Distribution Constant Constant

Value(Bytes) 1460 1460

Inter Arrival Time

Distribution Constant Constant

Value(µs) 10000 10000

Page 96: Maharastra EXTC  NetSim Experiment  Manual

To add an application, click add button in application property

Router Properties:

Accept the default properties for Router.

Wired Link Properties:

Accept the default properties for all Wired Links.

Simulation Time - 100 Sec

(Note: The Simulation Time can be selected only after doing the following two tasks,

Set the properties for Wired Nodes, Switches, Wired Links and Application.

Then click on Run simulation).

Sample 1: Wired Node B and Wired Node C transmit data to Wired Node D with the Packet

Inter Arrival Time as 10000 µs.

Likewise do the Sample 2 and Sample 3 by decreasing the Packet Inter Arrival Time as

5000 µs and 2500 µs respectively.

(Note: “Packet Inter Arrival Time (µs)” field is available in Application Properties)

Simulation Time - 100 Sec

(Note: The Simulation Time can be selected only after doing the following two tasks,

Set the properties for Wired Nodes, Router, Wired Links and Application.

Then click on Run simulation).

32.5 Comparison Chart:

(Note: The Number of Segments Sent, Segments Received and Datagram Sent, Datagram

Received will be available in the TCP Metrics and UDP Metrics of “Performance Metrics”

screen of NetSim)

Page 97: Maharastra EXTC  NetSim Experiment  Manual

32.6 Graph I

(Note: The “Packets transmitted successfully” for TCP is Segments Received and for UDP

is Datagram Received of the destination node i.e., Wired Node 3)

Number of packets transmitted successfully in TCP and UDP

32.7 Graph II

(Note: To get the “No. of packet lost”, For TCP, get the difference between Segments Sent

and Segments Received and for UDP, get the difference between Datagram Sent and

Datagram Received)

Number of lost packets in TCP and UDP

0

10000

20000

30000

40000

50000

Exp 1 Exp 2 Exp 3

Pac

kets

Tra

nsm

itte

d

Succ

essf

ully

Inter arrival time (Micro Sec)

TCP vs UDP

TCP

UDP

0

10

20

30

40

50

60

70

80

90

100

Exp 1 Exp 2 Exp 3

No

. of

Pac

ket

Lost

Experiment List

TCP

UDP

Page 98: Maharastra EXTC  NetSim Experiment  Manual

32.7.1 Inference:

Graph I, shows that the number of successful packets transmitted in TCP is greater than (or

equal to) UDP. Because, when TCP transmits a packet containing data, it puts a copy on a

retransmission queue and starts a timer; when the acknowledgment for that data is received,

the segment is deleted from the queue. If the acknowledgment is not received before the

timer runs out, the segment is retransmitted. So even though a packet gets errored or dropped

that packet will be retransmitted in TCP, but UDP will not retransmit such packets.

As per the theory given and the explanation provided in the above paragraph, we see in

Graph 2, that there is no packet loss in TCP but UDP has packet loss.

Page 99: Maharastra EXTC  NetSim Experiment  Manual

Study the throughputs of Slow start + 33.

Congestion avoidance (Old Tahoe) and Fast

Retransmit (Tahoe) Congestion Control

Algorithms.

33.1 Theory:

One of the important functions of a TCP Protocol is congestion control in the network. Given

below is a description of how Old Tahoe and Tahoe variants (of TCP) control congestion.

Old Tahoe:

Congestion can occur when data arrives on a big pipe (i.e. a fast LAN) and gets sent out

through a smaller pipe (i.e. a slower WAN). Congestion can also occur when multiple input

streams arrive at a router whose output capacity is less than the sum of the inputs. Congestion

avoidance is a way to deal with lost packets.

The assumption of the algorithm is that the packet loss caused by damaged is very small

(much less than 1%), therefore the loss of a packet signals congestion somewhere in the

network between the source and destination. There are two indications of packets loss: a

timeout occurring and the receipt of duplicate ACKs

Congestion avoidance and slow start are independent algorithms with different objectives.

But when congestion occurs TCP must slow down its transmission rate and then invoke slow

start to get things going again. In practice they are implemented together.

Congestion avoidance and slow start requires two variables to be maintained for each

connection: a Congestion Window (i.e. cwnd) and a Slow Start Threshold Size (i.e. ssthresh).

Old Tahoe algorithm is the combination of slow start and congestion avoidance. The

combined algorithm operates as follows,

1. Initialization for a given connection sets cwnd to one segment and ssthresh to 65535

bytes.

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2. When congestion occurs (indicated by a timeout or the reception of duplicate ACKs),

one-half of the current window size (the minimum of cwnd and the receiver‟s advertised

window, but at least two segments) is saved in ssthresh. Additionally, if the congestion is

indicated by a timeout, cwnd is set to one segment (i.e. slow start).

3. When new data is acknowledged by the other end, increase cwnd, but the way it increases

depends on whether TCP is performing slow start or congestion avoidance.

If cwnd is less than or equal to ssthresh, TCP is in slow start. Else TCP is performing

congestion avoidance. Slow start continues until TCP is halfway to where it was when

congestion occurred (since it recorded half of the window size that caused the problem in

step 2). Then congestion avoidance takes over.

Slow start has cwnd begins at one segment and be incremented by one segment every time an

ACK is received. As mentioned earlier, this opens the window exponentially: send one

segment, then two, then four, and so on. Congestion avoidance dictates that cwnd be

incremented by 1/cwnd, compared to slow start‟s exponential growth. The increase in cwnd

should be at most one segment in each round trip time (regardless of how many ACKs are

received in that RTT), whereas slow start increments cwnd by the number of ACKs received

in a round-trip time.

Tahoe (Fast Retransmit):

The Fast retransmit algorithms operating with Old Tahoe is known as the Tahoe variant.

TCP may generate an immediate acknowledgement (a duplicate ACK) when an out-of-order

segment is received out-of-order, and to tell it what sequence number is expected.

Since TCP does not know whether a duplicate ACK is caused by a lost segment or just a re-

ordering of segments, it waits for a small number of duplicate ACKs to be received. It is

assumed that if there is just a reordering of the segments, there will be only one or two

duplicate ACKs before the re-ordered segment is processed, which will then generate a new

ACK. If three or more duplicate ACKs are received in a row, it is a strong indication that a

segment has been lost. TCP then performs a retransmission of what appears to be the missing

segment, without waiting for a re-transmission timer to expire.

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33.2 Procedure:

Go to Simulation New Internetworks

Sample Inputs:

Follow the steps given in the different samples to arrive at the objective.

Sample 1.a: Old Tahoe (1 client and 1 server)

In this Sample,

Total no of Node used: 2

Total no of Routers used: 2

The devices are inter connected as given below,

Wired Node C is connected with Router A by Link 1.

Router A and Router B are connected by Link 2.

Wired Node D is connected with Router B by Link 3.

Page 102: Maharastra EXTC  NetSim Experiment  Manual

Set the properties for each device by following the tables,

Application Properties

Application Type Custom

Source_Id 4(Wired Node D)

Destination_Id 3(Wired Node C)

Packet Size

Distribution Constant

Value (bytes) 1460

Inter Arrival Time

Distribution Constant

Value (micro secs) 1300

Node Properties: In Transport Layer properties, set

TCP Properties

MSS(bytes) 1460

Congestion Control Algorithm Old Tahoe

Window size(MSS) 8

Router Properties: Accept default properties for Router.

Link Properties Link 1 Link 2 Link 3

Max Uplink Speed (Mbps) 8 10 8

Max Downlink Speed(Mbps) 8 10 8

Uplink BER 0.000001 0.000001 0.000001

Downlink BER 0.000001 0.000001 0.000001

Simulation Time - 10 Sec

Upon completion of simulation, “Save” the experiment.

(Note: The Simulation Time can be selected only after doing the following two tasks,

Page 103: Maharastra EXTC  NetSim Experiment  Manual

Set the properties of Node, Router& Link

Then click on Run Simulation button).

Sample 1.b: Tahoe (1 client and 1 server)

Open sample 1.a, and change the TCP congestion control algorithm to Tahoe (in Node

Properties). Upon completion of simulation, “Save” the experiment as sample 1.b.

Sample 2.a: Old Tahoe (2 clients and 2 servers)

In this Sample,

Total no of Wired Nodes used: 4

Total no of Routers used: 2

The devices are inter connected as given below,

Wired Node A and Wired Node B are connected with Router C by Link 1 and Link 2.

Router C and Router D are connected by Link 3.

Wired Node E and Wired Node F are connected with Router D by Link 4 and Link 5.

Wired Node A and Wired Node B are not transmitting data in this sample.

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Set the properties for each device by following the tables,

Application Properties Application 1 Application 2

Application Type Custom

Source_Id 5 6

Destination_Id 1 2

Packet Size

Distribution Constant Constant

Value (bytes) 1460 1460

Inter Arrival Time

Distribution Constant Constant

Value (micro secs) 1300 1300

NOTE: The procedure to create multiple applications are as follows:

Step 1: Click on the ADD button present in the bottom left corner to add a new

application.

Page 105: Maharastra EXTC  NetSim Experiment  Manual

Node Properties: In Transport Layer properties, set

TCP Properties

MSS(bytes) 1460

Congestion Control Algorithm Old Tahoe

Window size(MSS) 8

Router Properties: Accept default properties for Router.

Link Properties Link 1 Link 2 Link 3 Link 4 Link 5

Max Uplink Speed

(Mbps)

8 8 10 8 8

Max Downlink Speed

(Mbps)

8 8 10 8 8

Uplink BER 0.000001 0.000001 0.000001 0.000001 0.000001

Downlink BER 0.000001 0.000001 0.000001 0.000001 0.000001

Simulation Time - 10 Sec

Upon completion of simulation, “Save” the experiment.

(Note: The Simulation Time can be selected only after doing the following two tasks,

Set the properties of Node , Router & Link

Then click on Run Simulation button).

Sampe 2.b: Tahoe (2 clients and 2 servers)

Do the experiment as sample 2.a, and change the congestion control algorithm to Tahoe.

Upon completion of simulation, “Save” the experiment.

Page 106: Maharastra EXTC  NetSim Experiment  Manual

Sample 3.a: Old Tahoe (3 clients and 3 servers)

In this Sample,

Total no of Nodes used: 6

Total no of Routers used: 2

The devices are inter connected as given below,

Wired Node A, Wired Node B & Wired Node C is connected with Router D by Link 1,

Link 2 & Link 3.

Router D and Router E are connected by Link 4.

Wired Node F, Wired Node G & Wired Node H is connected with Router E by Link 5,

Link 6 & Link 7.

Wired Node A, Wired Node B and Wired Node C are not transmitting data in this sample.

Set the properties for each device by following the tables,

Application

Properties

Application 1 Application 2 Application 3

Application Type Custom

Source_Id 6 7 8

Destination_Id 1 2 3

Packet Size

Distribution Constant Constant Constant

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Value (bytes) 1460 1460 1460

Inter Arrival Time

Distribution Constant Constant Constant

Value (micro sec) 1300 1300 1300

Node Properties: In Transport Layer properties, set

TCP Properties

MSS(bytes) 1460 1460 1460

Congestion Control

Algorithm

Old Tahoe Old Tahoe Old Tahoe

Window size(MSS) 8 8 8

Router Properties: Accept default properties for Router.

Link

Properties

Link 1 Link 2 Link 3 Link 4 Link 5 Link 6 Link 7

Max Uplink

Speed

(Mbps)

8 8 8 10 8 8 8

Max

Downlink

Speed(Mbps)

8 8 8 10 8 8 8

Uplink BER 0.000001 0.000001 0.000001 0.000001 0.000001 0.000001 0.000001

Downlink

BER 0.000001 0.000001 0.000001 0.000001 0.000001 0.000001 0.000001

Simulation Time- 10 Sec

Upon completion of simulation, “Save” the experiment.

(Note: The Simulation Time can be selected only after doing the following two tasks,

Set the properties of Node, Router & Link

Then click on Run Simulation button).

Page 108: Maharastra EXTC  NetSim Experiment  Manual

Sample 3.b: Tahoe (3 clients and 3 servers)

Do the experiment as sample 3.a, and change the TCP congestion algorithm to Tahoe. Upon

completion of simulation, “Save” the experiment.

33.3 Output

Comparison Table:

TCP

Downloads Metrics

Slow start +

Congestion avoidance

Fast

Retransmit

1 client and 1

server

Throughput(Mbps) 5.894896 6.119152

Segments Retransmitted +

Seg Fast Retransmitted 198 200

2 clients and 2

servers

Throughput(Mbps) 8.617504 8.825408

Segments Retransmitted +

Seg Fast Retransmitted 397 415

3 clients and 3

servers

Throughput(Mbps) 9.17464 9.27392

Segments Retransmitted +

Seg Fast Retransmitted 408 426

Note: To calculate the “Throughput (Mbps)” for more than one application, add the

individual application throughput which is available in Application Metrics (or Metrics.txt)

of Performance Metrics screen. In the same way calculate the metrics for “Segments

Retransmitted + Seg Fast Retransmitted” from TCP Metrics Connection Metrics

33.4 Inference:

User lever throughput: User lever throughput of Fast Retransmit is higher when compared

then the Old Tahoe (SS + CA). This is because, if a segment is lost due to error, Old Tahoe

waits until the RTO Timer expires to retransmit the lost segment, whereas Tahoe (FR)

retransmits the lost segment immediately after getting three continuous duplicate ACK‟s.

This results in the increased segment transmissions, and therefore throughput is higher in the

case of Tahoe

Page 109: Maharastra EXTC  NetSim Experiment  Manual

Subnetting 34.

The objective can be executed in NetSim using the programming exercise available, under

programming user has to select IPV4 Addressing

34.1 How to Proceed:

The objective can be executed in NetSim using the programming exercise available, under

programming user has to select IPV4 Addressing Subnetting

Programming Guidelines

This section guides the user to link his/her own code for Sub-netting to NetSim.

Pre - Conditions

The user program should read the inputted scenario from text file named „Input‟ with

extension txt.

The user program after executing the concept should write the required output to a file named

„Output’ with extension txt.

The path of the input file and the output file can be viewed on clicking the Button “Path” in

NetSim.

Note:The temporary directory is navigated through the following step.

Run Type "%temp%" NetSim "Input.txt" and "Output.txt"

General Program Flow

The program begins with the Reading of the Inputs from the input file Input.txt.

Executing the required concept and,

The results of the program should be written into the output file Output.txt.

Page 110: Maharastra EXTC  NetSim Experiment  Manual

File Format

Input File Format Output File Format

Class=B

Network_Address=128.0.0.0

No_of_Subnets=2

Host_IP_Address=128.0.0.89

The Output file contains the Default mask (in decimal),

Network portion of Default mask (in binary), Host portion

of Default mask (in binary), Subnet mask bit value, Network

portion of Subnet mask (in binary), Host portion of Subnet

mask (in binary), Subnet mask (in decimal), number of zero

in host portion, number of host in each subnet, Host address,

subnet number of the given host, subnet address of the given

host and Subnet address, Starting address, Ending address,

Broadcast address of each subnet.

The Output File format

Default mask (in decimal)>

Network portion of Default mask (in binary)>Host portion

of Default mask (in binary)>

Subnet mask bit value>

Subnet mask (in decimal)>

Network portion of Subnet mask (in binary)>Host portion of

Subnet mask (in binary)>

Number of zero in host portion,>Number of host in each

subnet>

Host address>Subnet number of the given host >Subnet

address of the given host>

Subnet address>Starting address>Ending address>Broadcast

address >

.

.

.until number of subnet is reached

Sample Output text Format

255.255.0.0

11111111 11111111>00000000 00000000>

1>

255.255.128.0>

11111111 11111111 1>0000000 00000000>

15>32766>

Page 111: Maharastra EXTC  NetSim Experiment  Manual

128.0.0.89>1>128.0.0.0>

1>128.0.0.0>128.0.0.1>128.0.127.254>128.0.127.255>

2>128.0.128.0>128.0.128.1>128.0.255.254>128.0.255.255>

Interface Source Code

Interface source code written in C is given using this the user can write only the Leaky

bucket algorithm inside the function fnSubnet () using the variables already declared. To

view the interface source code, go to

NetSim Installation path / src / Programming/ Subnet.c

To find NetSim‟s Installation path right click NetSim icon and select

Open file location in Windows 7

Open file location in Windows Vista

Properties find target in Windows XP.

Sample Scenarios:

Objective - To understand the concept of Subnetting through programming.

How to Proceed –

The objective can be executed in NetSim using the programming exercise available, under

programming user has to select Subnetting,

Sample Inputs - In the Input panel the following steps need to be done,

SampleMode should be selected.

Select the Class Name

Select the Network Address from the given list.

Select the Number of Subnets from the given list.

Select the Host IP Address.

Page 112: Maharastra EXTC  NetSim Experiment  Manual

Then Run button need to be clicked. Refresh button can be used if new

Inputs have to be given.

Output - The following steps are under gone internally,

Subnet mask value is obtained.

Number of host in the each subnet is obtained

Subnet address, Starting address, Ending address and Broadcast address are

obtained.

Subnet address of the given Host IP address is obtained.

Once the sample experiment is done, then Refresh button can be clicked to

create New Samples.

Page 113: Maharastra EXTC  NetSim Experiment  Manual

Network Address 35.

35.1 How to Proceed:

The objective can be executed in NetSim using the programming exercise available, under

programming user has to select IPV4 Addressing Network Address

Programming Guidelines

This section guides the user to link his/her own code for Network Addresses to NetSim.

Pre - Conditions

The user program should read the input from text file named „Input‟ with extension txt.

The user program after executing the concept should write the required output to a file

named „Output’ with extension txt.

Note:The temporary directory is navigated through the following step.

Run Type "%temp%" NetSim "Input.txt" and "Output.txt"

General Program Flow

The program begins with the Reading of the Inputs from the input file Input.txt.

Executing the required concept and,

The results of the program should be written into the output file Output.txt.

File Format

Input File Output File

IP_Address=192.168.0.140

Prefix_Value=1

The Output File format

Binary value of IP Address>

Prefix value>

Binary value of Address mask>

Binary value of Network Address>

Decimal value of Network Address>.

Page 114: Maharastra EXTC  NetSim Experiment  Manual

Sample Output text Format

11000000 10101000 00000000 10001100 >1>

10000000 00000000 00000000 00000000>

10000000 00000000 00000000 00000000>

128>0>0>0>

Interface Source Code

Interface source code written in C is given using this the user can write only the

fnNetworkAddress () function using the variables already declared. To view the interface

source code, go to

NetSim Installation path / src / Programming/ NetworkAddress.c

To find NetSim‟s Installation path right click NetSim icon and select

Open file location in Windows 7

Open file location in Windows Vista

Properties find target in Windows XP.

Sample Scenarios:

Objective - To understand the concept of finding Network Address through programming.

Sample Inputs - In the Input panel the following steps need to be done,

SampleMode should be selected.

Select the IP Address

Select the Prefix value

Then Run button need to be clicked. Refresh button can be used if new

Inputs have to be given.

Output - The following steps are done internally,

Binary value of IP Address is obtained.

Page 115: Maharastra EXTC  NetSim Experiment  Manual

Binary value of Address Mask is obtained

Binary value of Network Address is obtained

Decimal value of Network Address is obtained

Once the sample experiment is done, then Refresh button can be clicked to

create New Samples.

Page 116: Maharastra EXTC  NetSim Experiment  Manual

Special Addresses 36.

36.1 How to Proceed:

The objective can be executed in NetSim using the programming exercise available, under

programming user has to select IPV4 Addressing Special Addresses

Programming Guidelines

This section guides the user to link his/her own code for Special Addresses to NetSim.

Pre - Conditions

The user program should read the input scenario from text file named „Input‟ with

extension txt.

The user program after executing the concept should write the required output to a file

named „Output’ with extension txt.

Note:The temporary directory is navigated through the following step.

Run Type "%temp%" NetSim "Input.txt" and "Output.txt"

General Program Flow

The program begins with the Reading of the Inputs from the input file Input.txt.

Executing the required concept and,

The results of the program should be written into the output file Output.txt.

File Format

Input File Output File

IP_Address=192.168.0.160

Prefix_Value=5

The Output File format

Binary value of IP Address>

32>Prefix value>Suffix value>

Binary value of Prefix Part> Binary value of

Suffix Part>

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Condition number in the table>condition>

Type of address>.

Sample Output text Format

11000000 10101000 00000000 10100000 >

32>5>27>

11000>000 10101000 00000000 10100000>

It doesn't Satisfy the four conditions>

Not a special address>

Interface Source Code

Interface source code written in C is given using this the user can write only the

fnSpecialAddress () function using the variables already declared. To view the interface

source code, go to

NetSim Installation path / src / Programming/ HammingCode.c

To find NetSim‟s Installation path right click NetSim icon and select

Open file location in Windows 7

Open file location in Windows Vista

Properties find target in Windows XP.

Sample Scenarios:

Objective - To understand the concept of Special Addresses through programming.

Sample Inputs - In the Input panel the following steps need to be done,

SampleMode should be selected.

Select the IP Address in slash notation

Then Run button need to be clicked. Refresh button can be used if new

Inputs have to be given.

Output - The following steps are done internally,

Binary value of IP Address is obtained.

Page 118: Maharastra EXTC  NetSim Experiment  Manual

Binary value of Address Mask is obtained

Prefix, Suffix values are obtained

Binary value of Prefix part and Suffix part are obtained

Type of address is obtained

Once the sample experiment is done, then Refresh button can be clicked to

create New Samples

Page 119: Maharastra EXTC  NetSim Experiment  Manual

Classless Inter Domain Routing (CIDR), CIDR 37.

Subnet addressing The objective can be executed in NetSim using the programming exercise available, under

programming user has to select IPV4 Addressing

37.1 Classless InterDomain Routing

37.1.1 How to Proceed:

The objective can be executed in NetSim using the programming exercise available, under

programming user has to select IPV4 Addressing Classless Inter Domain Routing

Programming Guidelines

This section guides the user to link his/her own code for Classless Inter Domain Routing to

NetSim.

Pre - Conditions

The user program should read the inputted scenario from text file named „Input‟ with

extension txt.

The user program after executing the concept should write the required output to a file

named „Output’ with extension txt.

The path of the input file and the output file can be viewed on clicking the Button “Path” in

NetSim.

Note:

The temporary directory is navigated through the following step.

Run Type "%temp%" NetSim "Input.txt" and "Output.txt"

General Program Flow

The program begins with the Reading of the Inputs from the input file Input.txt.

Executing the required concept and,

Page 120: Maharastra EXTC  NetSim Experiment  Manual

The results of the program should be written into the output file Output.txt.

File Format

Input File Format Output File Format

This gives the contents of the

„Input. Txt‟ from which the user has

to get the values.

The Input File contains:

Starting_IP_Address=150.0.0.0

No_of_Networks=3

No_of_Hosts_in_Network_1=512

No_of_Hosts_in_Network_2=1024

No_of_Hosts_in_Network_3=2048

Host_IP_Address=150.0.1.2

The Output file contains the First address, Last

address, Mask, Value and Network Address of

all the networks.

First Address: The Starting Address of the

Network

Last Address: The last address in the Network.

Mask: The Mask address (Mask should be 4 byte

format).

Number of Node: The number of nodes in the

network.

Value: The value will be either 0 or 1.

0 - The next line has the network address to

which the given host belongs.

1 - Means that the host does not belong to any

network.

Network Address: If the Value is 1 then the

network to which the host belongs is given.

Note: Each data will have a separate line and

each line will end with ">"

A Sample Output File Format

150.0.0.0>

150.0.1.255>

255.255.254.0>

512>

150.0.4.0>

150.0.7.255>

255.255.252.0>

1024>

150.0.8.0>

150.0.15.255>

Page 121: Maharastra EXTC  NetSim Experiment  Manual

255.255.248.0>

2048>

0>

150.0.0.0>

For each network there will be first address, last

address, mask and number of hosts. Since the

input is 3 networks, there are 3 set of outputs.

The last two lines give the details about whether

the host is present in any of the network.

Interface Source Code

Interface source code written in C is given using this the user can write only the CIDR inside

the function fnCIDR () using the variables already declared. To view the interface source

code, go to

NetSim Installation path / src / Programming/ CIDR.c

To find NetSim‟s Installation path right click NetSim icon and select

Open file location in Windows 7

Open file location in Windows Vista

Properties find target in Windows XP.

Sample Scenarios:

Objective - To Implement Classless InterDomain Routing (CIDR).

How to Proceed? - The objective can be executed in NetSim using the programming

exercise available, under programming user has to select Classless InterDomain Routing,

Sample Input - By using the Input Panel that is available on the left hand side a Sample

Scenario is created. The Steps involved in creating are as follows,

SampleMode should be selected.

Select the Starting IP Address from the given range.

Select the No. of Networks from the given range. Maximum of 6 networks

can be selected.

Page 122: Maharastra EXTC  NetSim Experiment  Manual

Select the No. of Hosts from the given range.

Click on Add button to add the No.ofHosts onto the Hosts Field. The use of

Add button depends on the No. of Networks selected. If a new No. of Hosts

has to be added then remove button can be used.

Select the Host IP Address.

Then Run button need to be clicked. Refresh button can be used if new

Inputs have to be given.

Output - The following steps are under gone internally,

Based on the Starting IP Address a table is obtained.

There are 4 columns available in the output table, i.e. First Address, Last

Address, CIDR Mask and No. of Hosts.

The First Address of the first network would be nothing but the Starting IP

Address which is selected. No. of rows in the table depends on the No. of

Networks selected.

The Last Address depends on depends on the No. of Host selected.

CIDR Mask is obtained internally by using the following formula,

CIDR Mask = 32 - (log (No. of Host) / log (2))

Once the sample experiment is done, then Refresh button can be clicked to

create New Samples.

Page 123: Maharastra EXTC  NetSim Experiment  Manual

Implementation of QoS in IEEE 802.11e 38.

Network

38.1 Theory:

IEEE 802.11e Medium Access Control (MAC) is an emerging supplement to the IEEE

802.11 Wireless Local Area Network (WLAN) standard to support Quality-of-Service (QoS).

The 802.11e MAC is based on both centrally-controlled and contention-based channel

accesses. The standard is considered of critical importance for delay-sensitive applications. It

offers all subscribers high-speed Internet access with video, audio, and voice over IP.

38.2 Procedure:

Step 1:

Go to Simulation New Internetworks

Sample 1:

Step 2:

Create scenario as per the screen shot:

Devices Required:

2 Wireless Node, 1 Access point,

1 Router, 1 Wired Node

Page 124: Maharastra EXTC  NetSim Experiment  Manual

Step 3:

Access Point Properties AP C

Global Properties

X_Coordinate 250

Y_Coordinate 100

Step 4:

Wireless Node Properties Wireless Node B Wireless Node C

Global Properties

X_Coordinate 300 250

Y_Coordinate 100 150

Step 5:

Node properties: Disable TCP in all nodes in Transport layer as follows:

Wireless Link Properties:

Right click on Wireless link and Change the channel characteristics as “No Path Loss”

Channel Characteristics No Path Loss

Page 125: Maharastra EXTC  NetSim Experiment  Manual

Wired Link Properties:

Right click on Wired link and Change the Bit Error Rate

Wired Link Properties

Bit Error Rate 0

Access Point Properties:

Right click on access point properties. In interface1_Wireless, enable IEEE802.11e and set

the buffer size as 5 as shown in below figure:-

Wireless Node Properties:

Right click on Wireless Node and in Interface1_Wireless, enable IEEE802.11e

Page 126: Maharastra EXTC  NetSim Experiment  Manual

Step 6:

Select the Application Button and click on the gap between the Grid Environment and the

ribbon. Now right click on Application and select Properties as shown below:

NOTE: The procedure to create multiple applications are as follows:

Step 1: Click on the ADD button present in the bottom left corner to add a new

application.

Application Type Voice CBR

Source ID 1 (Wired Node E) 1(Wired Node E)

Destination ID 4 ( Wireless Node C) 5( Wireless Node B)

Codec Custom -

Packet Size

Distribution Constant Constant

Value(Bytes) 1000 1000

Inter Arrival Time

Distribution Constant Constant

Value(µs) 800 800

Page 127: Maharastra EXTC  NetSim Experiment  Manual

Simulation Time – 10 sec

After completion of the experiment, “Save” the experiment as Sample 1.

Sample 2:

Open Sample 1, and disable IEEE_802.11e in both Access point and Wireless Node

properties and run the simulation for 10 seconds.

38.3 Output

Comparison Table:

38.4 Inference

802.11e is a proposed enhancement to the 802.11a and 802.11b Wireless LAN (WLAN)

specifications. It offers quality of service including which prioritization of voice, video and

data transmissions. Hence Throughput is obtained for voice transmission.

IEEE 802.11e

Application Generation rate

(Mbps)

Throughput

(Mbps)

Delay

(Micro. Sec.)

Enable Voice 10 4.67 2782736.5

CBR 10 0.0 0

Disable Voice 10 2.28 4099938.2

CBR 10 2.28 4100423.3

Page 128: Maharastra EXTC  NetSim Experiment  Manual

ETE 802 TELECOM NETWORK MANAGEMENT

Study the effect of Peak Cell Rate (per Sec) 39.

and Cell Delay Variation Tolerance on the

performance of an ATM Networks

39.1 Theory:

QoS Parameters

Primary objective of ATM is to provide QoS guarantees while transferring cells across the

network. The three main QoS parameters specified for ATM which indicate the performance

of the network are:

Cell Transfer Delay (CTD): The delay experienced by a cell between the first bit of

the cell is transmitted by the source and the last bit of the cell is received by the

destination.

Peak to Peak Cell Delay Variation (CDV): The difference of the maximum and

minimum CTD experienced during the connection.

Cell Loss Ratio (CLR): The percentage of cells lost in the network due to error or

congestion that are not received by the destination.

Peak Cell Rate (PCR) specifies the rate in cells per sec that a source is never allowed to

exceed.

Procedure:

How to Create Scenario & Generate Traffic:

Please navigate through the below given path to,

Create Scenario: “Simulation New Legacy Networks ATM”.

Page 129: Maharastra EXTC  NetSim Experiment  Manual

Inputs

Follow the steps given in the different samples to arrive at the objective.

In this Sample,

Total no of CPEs used: 2

Total no of Switches used: 2

The devices are inter connected as given below,

CPE 1 and CPE 2 are connected via Link 1 and Link 3 to Switch 1 and Switch 2

respectively.

Switch 1 is connected to Switch 2 by Link 2.

Set the properties of Switch and CPE by following the tables for each sample,

Switch Properties Switch 1 Switch 2

Scheduling Technique

Priority Priority

Buffer Size (KB) 8 8

Link Properties Link 1 Link 2 Link 3

Bit Error Rate No Error No Error No Error

Physical Medium E0 E0 E0

Distance (km) 1 1 1

Page 130: Maharastra EXTC  NetSim Experiment  Manual

Inputs for Sample 1

CPE Properties:

Inputs for Sample 2, Sample 3, Sample 4 and Sample 5:

The following properties are changed for Sample 2, Sample 3, Sample 4 and Sample 5: (rest

is same as in Sample 1)

CPE Properties Sample 2 Sample 3 Sample 4 Sample 5

Peak Cell Rate

(cells/second)

2000 3000 4000 5000

Cell Delay Variation

Tolerance (µs)

2000 3000 4000 5000

Simulation Time – 10 sec

Output

To view the output by using NetSim Sample experiments need to be added onto the

Analytics interface.Given below is the navigation for analytics -

“SimulationAnalytics”

Select the experiments by selecting

Legacy Networks

Select the Experiments (Note: Click one experiment after another to compare the

experiments in the Analytics interface).

Select the Metric: Queuing Delay (ms)

Page 131: Maharastra EXTC  NetSim Experiment  Manual

Comparison Charts:

39.2 Inference

When the Peak Cell Rate and Cell Delay Variation Tolerance are changed from 1000 to

5000, the Number of Cells transmitted increases. This is because the conformance of the

traffic depends on the Peak Cell Rate and the Cell Delay Variation Tolerance. As the number

of cells transmitted increases, queuing delay also increases.

Page 132: Maharastra EXTC  NetSim Experiment  Manual

Network performance analysis with an ATM 40.

switch implementing different scheduling

techniques like First in First out (FIFO),

Priority, and Round Robin

40.1 Theory

In an ATM network, scheduling of cells is the major task of any ATM switch. Scheduling is

the process by which the ATM switch determines the sequence of flow of the cells in

network. The scheduling is done on various properties like service type, cell category, queue

length, arrival time etc.

First In First out (FIFO): FIFO is the simplest way of scheduling. As the name suggests, in

this technique, the preference is given to that cell which comes first in the queue irrespective

of its priority value. The one which comes next waits until the first finishes. The drawback of

this technique is that some cells of very high priority like audio service encounter extra delay

that is not ignorable.

Priority: In this technique, each cell is assigned a certain priority value based on its traffic

parameters. The scheduler checks the availability of highest priority cells and schedules them

before going for the lower priority cells. The drawback of this algorithm is that cells of

lowest priority starve for the resources when there are a large number of higher priority cells.

Round Robin: In this technique, the scheduler gives equal preference for all priority types.

Therefore, scheduler processes one cell of each priority type (If available) before going for

the next cell and cycles through them. Here starvation never occurs because no priority is

given. Round robin scheduling may not be desirable if QoS of the different priority type are

highly variable.

Page 133: Maharastra EXTC  NetSim Experiment  Manual

40.2 Procedure:

In this experiment, we are going to analyze the link Utilization (%) of the outgoing link from

an ATM switch

First in First out (FIFO):

In NetSim, Select “SimulationNewLegacy Networks ATM”

How to Create Scenario & Generate Traffic:

Inputs

Follow the steps given in the different samples to arrive at the objective.

In all Samples,

Total no of CPEs used: 4

Total no of ATM switches used: 2

The devices are interconnected as given below

CPE 1 is connected to Switch 1 by Link 1.

CPE 2 is connected to Switch 1 by Link 2.

CPE 3 is connected to Switch 2 by Link 4.

CPE 4 is connected to switch 2 by Link 5.

Switch 1 and Switch 2 are connected via Link 3.

Page 134: Maharastra EXTC  NetSim Experiment  Manual

Set the properties for each device by following the tables,

Switch Properties Switch 1 Switch 2

Scheduling technique FIFO FIFO

Buffer size 4096 KB 4096 KB

CPE 1 Properties CPE 1

Destination CPE 3

Transmission Type Point to Point

Traffic Type Data

Scheduling FIFO

Peak cell rate (cells/sec) 99999

Cell delay Variation tolerance (µs) 99999

GCRA type VSA

Data Input Configuration for CPE 1:

Application Data Size

Distribution Constant

Mean Application Data Size (bytes) 10000

Inter arrival time

Distribution Constant

Mean Inter-arrival time (µs) 10000

Generation rate (Mbps) 8

CPE 2 Properties CPE 2

Destination CPE 4

Transmission Type Point to Point

Traffic Type Voice

Scheduling FIFO

Page 135: Maharastra EXTC  NetSim Experiment  Manual

Peak cell rate (cells/sec) 99999

Cell delay Variation tolerance (µs) 99999

GCRA type VSA

Voice Input Configuration for CPE 2:

Codec Constant

Application Data Size (bytes) 10000

Inter-arrival time (µs) 20000

Service Type CBR

Generation rate (Mbps) 4

Link Properties Link 1 Link 2 Link 3 Link 4 Link 5

Bit Error Rate

(BER)

No Error No Error No Error No Error No Error

Physical medium E2 E2 E0 T1 T1

Data Rate (Mbps) 8.448 8.448 0.064 1.54 1.54

Distance 1 1 1 1 1

Simulation Time –10 sec

(Note: The Simulation Time can be selected only after doing the following two tasks,

Set the properties of CPE and Switch,

Then click on Run Simulation button).

“Save” it, upon completion of the experiment.

Page 136: Maharastra EXTC  NetSim Experiment  Manual

Output:

Select the metrics Utilization and Delay report (Link). Note down the link utilization of Link

4 and Link 5.

Priority:

Follow the same steps as above in First in First out (FIFO) to create scenario and set the

properties of all devices.

Edit the properties of Switch as follows:

Switch Properties Switch 1 Switch 2

Scheduling technique Priority FIFO

Buffer size 4096 KB 4096 KB

Simulation Time –10 sec

(Note: The Simulation Time can be selected only after doing the following two tasks,

Set the properties of CPE and Switch,

Then click on Run Simulation button).

“Save” it, upon completion of the experiment

Page 137: Maharastra EXTC  NetSim Experiment  Manual

Output:

Select the metrics Utilization and Delay report (Link). Note down the link utilization of Link

4 and Link 5.

Round Robin:

Follow the same steps as above in First in First out (FIFO) to create scenario and set the

properties of all devices.

Edit the properties of Switch as follows:

Switch Properties Switch 1 Switch 2

Scheduling technique Round Robin FIFO

Buffer size 4096 KB 4096 KB

Simulation Time –10 Sec.

(Note: The Simulation Time can be selected only after doing the following two tasks,

Set the properties of CPE and Switch,

Then click on Run Simulation button).

“Save” it, upon completion of the experiment.

Page 138: Maharastra EXTC  NetSim Experiment  Manual

Output:

Select the metrics Utilization and Delay report (Link). Note down the link utilization of Link

4 and Link 5.

Comparison:

Page 139: Maharastra EXTC  NetSim Experiment  Manual

Traffic analysis:

CPE 1 is transmitting Data traffic (being generated at 8 Mbps) to CPE 3 through links 1, 3,

and 4. CPE2 transmitting voice traffic (being generated at 4 Mbps) to CPE4 through link 2,

3, and 5. Here, voice traffic has priority over data traffic.

Link speed of link 1 and 2 is high (8.448 mbps) as compared to data rate and also the PCR

and CDVT of CPE1 and CPE 2 are high. So there is a low probability that these cells will be

dropped. Therefore, all the cells reach switch1 where scheduling will happens.

Link speed of link 3 is very low (0.064 mbps) which means it does not have enough

resources to handle the cells. Hence, it will only pass those cells that have high priority

(based on Scheduling technique). Link speed of 4 and 5 is high compared to link 3 and so

there is no queue is buildup on switch 2. Based on what type of cells pass through link 3,

determines the utilization of the link 4 and link 5.

40.3 Inference:

As we see in chart 1 and table 1, the utilization of link 4 is double of link 5 in case of FIFO.

Because, in case of FIFO, scheduler gives preference to which cell comes first. Note that the

data rate of CPE1 is double than CPE2 data rate and link speed is same hence switch 1 gets

two cells from CPE 1 and one cell from CPE2 and schedules two packets of CPE1 and one

packet of CPE2. Therefore, the number of packet transmitted through link 4 is double than

link 5 and hence utilization is also double.

Page 140: Maharastra EXTC  NetSim Experiment  Manual

In case of priority, the utilization of the link 4 is 0.006 % and link 5 is 4.138%. This is

because the ATM scheduler gives priority to the voice traffic (generated by CPE2 to CPE4

via link 2, 3 and 5) over data traffic (generated by CPE 1 to CPE 3 via link 1, 3 and 4). The

generation rate of voice traffic is 4 Mbps which is much greater than the link speed of link 3

(0.064 Mbps). Hence, scheduler only schedules voice traffic and data traffic keeps waiting in

the queue.

In case of round robin the utilization of both the links is the same. Because, in case of Round

robin, scheduler schedules the packet in circular fashion implying one packet from CPE1 and

one packet from CPE2. Note that the data rate of CPE1 and CPE2 is sufficiently high to

ensure presence of a packet in the buffer from both the CPEs. Therefore, the number of

packets transmitted through link 4 is same as link 5 and hence utilization is also same.