Basic Networking What is Network ? A network is the most cost-effective way to share a collection of communication equipment such as PC's, servers, printers,

Basic NetworkingWhat is Network ?

A network is the most cost-effective way to share a collection of communication equipment such as PC's, servers, printers, and modems that has been connected together by cables. A network helps people work collectively, not just individually. 1

Network Diagram

How Network is connected

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Simple Computer Network How the file sharing takes

place in a simple computer network

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The Basic Network(H/W & S/W requirements)

Server or Client Workstation Networking Interface Card's (NIC) Cabling Networking Operating System such

as Windows NT/2000, XP, 2003 Server, Vista, Linux etc.

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Terms of Networking Peer-to-Peer, this is commonly two PC

connected together to share files or a printer.

Local Area Network (LAN), this is probably the most popular in smaller applications. This comes down to many computers interconnected in an office or home. This can be anywhere from two computers or hundreds in one physical area.

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Terms of Networking Wide Area Network (WAN), boils down

to computer networks that are far apart and connect via phone, satellite, and so forth.

Node, this is just another name for the client computer or the computer using the network. You are in essence a node right now using this website which is located on a server over the Internet.

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Terms of Networking Topology, is the geometric arrangement of

the network. This is more or less how the network is arranged. We will discuss this one more later on.

Protocol(Network comm. Language & procedure), The protocol is a ways of communication for the network. Think of it as trying to speak French to an English computer. We need a protocol so they can understand one another.

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Terms of Networking Data Packets, messages of data that

has been sent over your network. Architecture's, this comes down to

peer to peer or the client server applications. In the peer to peer we share resources of each other's computers equally and the client server is one computer with all the host files and data.

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Terms of Networking

Right now you are connecting to my server for this web page as a client/server architecture.

Media, this amounts to how your network is physically connected. Most LAN's connect with a copper wire or cable coaxial. Some newer technologies also allow you to connect wireless using your existing power outlets.

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Types of Network

LAN – Local Area Network

MAN – Metropolitan Area Network

WAN – Wide Area Network

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LAN (Local Area Network) A local area network may serve as few as

two or three users (for example, in a home network) or many as thousands of users.

Local-area networks (LANs) evolved around the PC revolution. LANs enabled multiple users in a relatively small geographical area to exchange files and messages, as well as to access shared resources such as file servers and printers. 11

LAN (Local Area Network) Is a group of computers and

associated device that share a common communications line or wireless link and typically share the resources of a single processor or server within a small geographic area (for example, within an College Building).

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LAN (Local Area Network) - Benefits

LAN consist of the following components:

Computers Network interface cards Peripheral devices Networking media Network devices

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LAN (Local Area Network) -Technologies

Common LAN technologies include the following:

Ethernet Token Ring FDDI

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LAN (Local Area Network) -Technologies Ethernet

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LAN (Local Area Network) -Technologies

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LAN (Local Area Network) -Technologies FDDI (Fiber Distributed Data

Interface)

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Fiber Optics Infrared light is transmitted through

fiber and confined due to total internal reflection.

Fibers can be made out of either plastic or glass.

Used for high speed backbones and pipes over long distances.

Comparatively expensive. 18

Fiber Optic – Cut View Cable

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LAN (Local Area Network) -Characteristics

Topology The geometric arrangement of

devices on the network or the shape of a local-area network (LAN) or other communications system.

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Protocols The rules and encoding

specifications for sending data. The protocol defines the format and meaning of the data that is exchanged. The protocols also determine whether the network uses a peer-to-peer or client/server architecture.

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Protocols - Roles

Addressing and routing of messages Error detection Recovery Sequence and flow controls Example: HTTP protocol for

communication between web browsers

and servers.22


Media Devices can be connected by

twisted-pair wire, coaxial cables, or fiber optic cables. Some networks do without connecting media altogether, communicating instead via radio waves.

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LAN (Local Area Network) –Topology types

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Bus topology: All devices are connected to a

central cable, called the bus or backbone. Bus networks are relatively inexpensive and easy to install for small networks. Ethernet systems use a bus topology. In Simple way we can say us (All devices share a common wire to transmit and receive data through using an arbitration method.)

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Diagram of Bus Topology

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Industrial BUS TOPOLOGY

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LAN (Local Area Network) –Topology types Star topology:

All devices are connected to a central hub. Star networks are relatively easy to install and manage, but bottlenecks can occur because all data must pass through the hub. This is not much of a problem anymore with the widespread deployment of switches. At the central point we usually see a device generically called a hub or switch. 28

Diagram of Star Topology

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Industrial STAR TOPOLOGY

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Ring topology: All devices are connected to one

another in the shape of a closed loop, so that each device is connected directly to two other devices, one on either side of it. Ring topologies are relatively expensive and difficult to install, but they offer high bandwidth and can span large distances. 31

LAN (Local Area Network) –Topology types A ring is created to which each

device attaches. A special signal, called a token travels around the ring letting it know that it is that device’s turn to transmit.

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Diagram of Ring Topology

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Industrial RING TOPOLOGY

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NETWORKS ARE BROKEN INTO 3 TOPOLOGIES. THEY ARE:

BUS TOPOLOGY

STAR TOPOLOGY

RING TOPOLOGY

Basics of Networking

BUS TOPOLOGY ALLOWS INFORMATION TO BE DIRECTED FROM ONE COMPUTER TO THE OTHER. LOTS OF BINARY COLLISION THOUGH.


STAR TOPOLOGY IS THE MOST COMMON TYPE USED. ALL COMPUTERS ARE ATTACHED TO A HUB. LESS COLLISIONS AND MOST EFFICIENT.


RING TOPOLOGY- USES A TOKEN TO PASS INFORMATION FROM 1 COMPUTER TO THE OTHER. A TOKEN IS ATTACHED TO THE MESSAGE BY THE SENDER TO IDENTIFY WHICH COMPUTER SHOULD RECEIVE THE MESSAGE. AS THE MESSAGE MOVES AROUND THE RING, EACH COMPUTER EXAMINES THE TOKEN. IF THE COMPUTER IDENTIFIES THE TOKEN AS ITS OWN, THEN IT WILL PROCESS THE INFORMATION.


A DISADVANTAGE OF A TOKEN RING IS IF ONE COMPUTER IS BROKEN OR DOWN, THE MESSAGE CANNOT BE PASSED TO THE OTHER COMPUTERS.


Wireless Topology Not really a specific topology since a

workstation in a wireless LAN can be anywhere as long as it is within transmitting distance to an access point

Speeds up to 50 Mbps possible Workstations reside within a basic service set, while multiple basic service sets create an extended service set.

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Basic Wireless Network

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Comparisons of Various Topologies

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Simple LAN Connection - College

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(MAN) - Metropolitan-area networks A MAN usually consists of two or

more LANs in a common geographic area. Typically, a service provider is used to connect two or more LAN sites using private communication lines or optical services. A MAN can also be created using wireless bridge technology by beaming signals across public areas.

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WAN – (Wide Area Network) WANs interconnect LANs, which then

provide access to computers or file servers in other locations. Because WANs connect user networks over a large geographical area, they make it possible for businesses to communicate across great distances. WANs allow computers, printers, and other devices on a LAN to be shared with distant locations.

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WAN – (Wide Area Network)

WANs provide instant communications across large geographic areas.

Collaboration software provides access to real-time information and resources and allows meetings to be held remotely.

WANs have created a new class of workers called telecommuters. These people never have to leave their homes to go to work.

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WAN Design Operate over a large and

geographically separated area. Allow users to have real-time

communication capabilities with other users.

Provide full-time remote resources connected to local services.

Provide e-mail, Internet, file transfer, and e-commerce services.

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WAN Technologies

Modems Integrated Services Digital Network

(ISDN) Digital subscriber line (DSL) Frame Relay T1, E1, T3, and E3 Synchronous Optical Network

(SONET)48

WAN Diagram

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Open System Interconnection Model Layers 7 Application 6 Presentation 5 Session 4 Transport 3 Network 2 Data Link 1 Physical

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OSI Layer Structure

Physical layer - (defines the physical characteristics of the network)

Data-link layer - (provides safe communication of data over the physical network)

Network layer - (handles connection to the network by the higher layers)

Transport layer - (provides end-to-end errors detection and correction) 51

OSI Layer Structure

Session layer - (manages sessions among applications)

Presentation layer - (provides standard data representations for applications)

Application layer- (applications connected to the network)

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OSI Layer Brief Overview Physical layer: ensures a safe and

efficient travel of data; consists of electronic circuits for data transmission etc.

Data link layer: in charge of data encapsulation under the form of packets and their interpretation at the physical layer.

Network layer: in charge of packets transmission from a source A to a destination B. 53

OSI Layer Brief Overview Transport layer: in charge of the

delivery of packets from a source A to a destination B

Session layer: in charge of the management of network access.

Presentation layer: determines the format of the data transmitted to applications, data compressing/decompressing, encrypting etc. 54

OSI Layer Brief Overview

Application layer: contains the applications which are used by the end-user, such as Java, Word etc.

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Network Basic Cabling

CablesIn the network you will

commonly find three types of cables used these are the, coaxial cable, fiber optic, and twisted pair.

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Coaxial Cables: A single insulated inner wire is surrounded by a cylindrical conductor which is covered with a shield; it transmits electromagnetic signals. Coaxial cable is classified into two categories: baseband (uses digital signals) and broadband (uses analog signals) coaxial cable.

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Coaxial Cables:Thick Coaxial Cable, this type cable is

usually yellow in color and used in what is called thick nets, and has two conductors. This coax can be used in 500-meter lengths. The cable itself is made up of a solid center wire with a braided metal shield and plastic sheathing protecting the rest of the wire.

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Coaxial Cable: Diagram

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Thin Coaxial Cable, as with the thick coaxial cable is used in thick nets the thin version is used in thin nets. This type cable is also used called or referred to as RG-58. The cable is really just a cheaper version of the thick cab

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Coaxial Cable Specifications Other Names: Yellow Cable, Thick wire Medium: Coaxial cable Data Rate:10 Mbps Segment Length: max. 500 m Users: max.100 Tranceivers/segment Termination:50 Ohm, 1 Watt Connection: via Tranceiver with

Vampire tap61

Network Basic Cabling Twisted Pair Cables: Two insulated

copper wires twisted together in a regular spiral pattern; one pair establishes one communication link; it transmits electromagnetic signals. Twisted pairs are distinguished between shielded and unshielded twisted pairs according to their protection against electromagnetic fields.

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Unshielded Twisted Pair (UTP), this is the most popular form of cables in the network and the cheapest form that you can go with. The UTP has four pairs of wires and all inside plastic sheathing. The biggest reason that we call it Twisted Pair is to protect the wires from interference from themselves. Each wire is only protected with a thin plastic sheath.

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Unshielded Twisted Pair (UTP)

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•Straight though cables or also known as patch cables

•Cross-over cables

The difference in the cables are the way the wiresare connected within the RJ45. I have attached a sheet for you in your package.


Wiring: 1-3 White/Orange2-6 Orange3-1 White/Green6-2 Green4-4 Blue5-5 White/Blue7-7 White/Brown8-8 Brown

Typical Crossover Cable



Shielded Twisted Pair (STP), is more common in high-speed networks. The biggest difference you will see in the UTP and STP is that the STP use's metallic shield wrapping to protect the wire from interference.

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Shielded Twisted Pair

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Twisted Pair Cable Specifications

Medium: 2-pair Category 5 Cable Data Rate:

10 Mbit/s (10BASE-T),100 Mbit/s (100BASE-TX)Segment Length: max. 100 m (point-to-point)

Connection: RJ45 Connector

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Fiber Optic: consists of three concentric sections, the core (a fiber conducting optical rays), the cladding (reflecting optical rays) and the jacket (surrounding one or many fibers to protect them); transmits optical signals, which must be transformed to electromagnetic signals

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Fiber Optic - Diagram

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Fiber Optics Specifications

Medium: 2 Fiber Pairs (50/125 or 62, 5/125)

Data Rate:10 Mbit/s (10BASE-FL),100 Mbit/s (100BASE-FX)

Segment Length: max. 2000 m (point-to-point)

Connection: ST Connector (10-BASE-FL)Duplex SC Connector (100BASe-FX)

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THE NETWORK LAYER

If you look at the IP Address, the number are brokeninto different categories.

216. 27.61.137

Classification Hosts

216. 27.61.137

Octets


Classifications can be broken into 3 classes. They are:

Class A - Only the first octet is used for addressing and the balance used for hosts.

Class B - The first two octet are used for addressing and the balance used for hosts.

Class C - The first three octet are used for addressing and the balance used for hosts.


Every machine on the Internet has a unique

identifying number, called an IP Address.

A typical IP address looks like this:

216.27.61.137

But computers communicate in binary form.


The same IP address in binary:

11011000.00011011.00111101.10001001

216.27.61.137


Class A - This class is for very large networks,

such as a major international company might have.

IP addresses with a first octet from 1 to 126 are

part of this class.


Class B - This class is used for medium-sized networks.

A good example is a large college campus.

IP addresses with a first octet from 128 to 191

are part of this class. Class B addresses also include

the second octet as part of the Net identifier.


Class C - Class C addresses are commonly used for

small to mid-size businesses. IP addresses

with a first octet from 192 to 223 are part of this

class. Class C addresses also include the second

and third octets as part of the Net identifier.


Advantages and Disadvantages Each transmission media has its own

advantages and disadvantages. They differ in costs, capacity, possible length, and electromagnetic isolation. Which media to be chosen depends on three other characterization features of LANs: firstly, which topology is to be implemented. Secondly, which capacity and reliability are needed.

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Network Hardware - HUB

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Network Hardware - HUB An unintelligent network device that

sends one signal to all of the stations connected to it.

• Traditionally, hubs are used for star topology networks, but they are often used with other configurations to make it easy to add and remove computers without bringing down the network.

• Resides on Layer 1 of the OSI model82

Network Hardware - SWITCH

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Network Hardware - SWITCH Split large networks into small

segments, decreasing the number of users sharing the same network resources and bandwidth.

Understands when two devices want to talk to each other, and gives them a switched connection

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Network Hardware - SWITCH Helps prevent data collisions and

reduces network congestion, increasing network performance.

Most home users get very little, if any, advantage from switches, even when sharing a broadband connection.

Resides on Layer 2 of the OSI model.85

Network Hardware - ROUTER

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Network Hardware - ROUTER A device that connects any number of

LANs. Uses standardized protocols to move

packets efficiently to their destination. More sophisticated than bridges,

connecting networks of different types (for example, star and token ring)

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Network Hardware - ROUTER Forwards data depending on the

Network address (IP), not the Hardware (MAC) address.

Routers are the only one of these four devices that will allow you to share a single IP address among multiple network clients.

Resides on Layer 3 of the OSI model.88

Thank You

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Documents

Basic Networking What is Network ? A network is the most cost-effective way to share a collection of communication equipment such as PC's, servers, printers,