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UNIT 1
INTRODUCTION TO
NETWORKING
LEARNING OUTCOME
Student should be able to:
1. List advantages of networked computing relative to standalone computing.
2. Differentiate between peer-to-peer networks and client/server networks
3. Differentiate Local Area Network (LAN), Metropolitan Area Network (MAN), Wide Area Network (WAN)
WHAT IS NETWORKING?
Networking is the practice of linking two or more computing devices together for the purpose of sharing data.
Networks are built with a mix of computer hardware and computer software.
A network is nothing more than two or more computers connected to each other so that they can exchange information, such as email messages or documents or share resources, such as disk storage.
CHARACTERISTIC OF
COMPUTER NETWORK
http://www.functionx.com/networking/Lesson01.htm
NETWORKING
Advantages
A user can logon to a computer anywhere on the
network and access their
work files from the file
server.
Computers can be managed centrally - with the same
software installed on each
one.
Time - it is much faster to install an application once
on a network - and copy it
across the network to every
workstation.
Disadvantages
If something goes wrong with the file
server the whole
network.
The technical skills needed to manage a
network are much
higher than working on
a stand-alone
computer.
http://www.ictgnvq.org.uk/unit10/advantages_and_disadvantages.htm
NETWORK VS STAND ALONE
Advantages Sharing printers, plotters,
modems etc saves money and time.
Security - the Network Manager can allocate usernames and passwords to all users to try to prevent unauthorized access.
I is easy and convenient to monitor users for example websites visited or documents printed this can be done using software running on the server.
Disadvantages It can be frustrating to print to
a printer in another room and then find after a long trek that there is no paper in the printer!
Users may use up too much of the storage space and this may cause problems on the network.
Users may use too much bandwidth for example when listening to music files or watching video clips preventing others from using the network facilities properly.
http://www.ictgnvq.org.uk/unit10/advantages_and_disadvantages.htm
PEER-TO-PEER NETWORKS
(P2P)
PEER-TO-PEER NETWORKS
(P2P) 1. The simplest form of a network.
2. Traditional p2p networks typically consist of two or more general purpose personal computer, with modest processing capabilities.
3. By default, no computer on a peer to peer has more authority than another.
4. However, each computer can be configured to share only some of its resources and prevent access to other resources.
PEER-TO-PEER NETWORKS
(P2P) 1. Each computer holds its files and resources.
Other computers can access these resources but a computer that has a particular resource must be turned on for other computers to access the resource it has. For example, if a printer is connected to computer A and computer B wants to printer to that printer, computer A must be turned ON.
2. A Peer to peer capable network operating system, such as Windows 95, Windows 98 and Windows for Workgroups are usually the best choices for home and small office networks.
ADVANTAGES AND
DISADVANTAGES OF P2P
Advantages
Network is fast and simple to setup and
maintain.
Less expensive to set up and maintain than
other types of
networks.
No need for network administrator.
Disadvantages
Not secure enough. In simple installations, data and other resources shared by network users can be easily discovered and used by unauthorized people.
Not practical for larger computer.
Not flexible as network grows larger, adding or changing significant elements of the network may be difficult.
CLIENT-SERVER NETWORKS
CLIENT-SERVER NETWORKS
A network that uses a server to enable clients to share data, data storage space, and devices is known as a client/server network.
Another way of designing a network is to use a central computer, known as a server, to facilitate communication and resource sharing between other computers on the network, which are known as clients.
http://www.functionx.com/networking/Lesson06.htm
CLIENT-SERVER NETWORKS
Every computer on a client/server network acts as a client or a server. (It is possible, but uncommon, for some computers to act as both.)
Clients on a network can still run applications from and save data to their local hard disk. But by connecting to a server, they also have the option of using shared applications, data, and devices.
CLIENT-SERVER NETWORKS
Clients do not share their resources directly with each other, but rather use the server as an intermediary through connectivity devices such as switches or routers.
Client-Server network operating systems, such as Windows NT and Novel NetWare are better for larger scale organizations that require fast network access for video, publishing, multimedia, spreadsheet, database, and accounting operations.
ADVANTAGES OF CLIENT-
SERVER NETWORKS
User logon accounts and passwords for anyone on a server-based network can be assigned in one place.
Access to multiple shared resources (such as data files or printers) can be centrally granted to a single user or groups of users.
Problems on the network can be monitored, diagnosed, and often fixed from one location.
ADVANTAGES OF CLIENT-
SERVER NETWORKS
Servers are optimized to handle heavy processing loads and
dedicated to handling requests from
clients, enabling faster response time.
Because of their efficient processing and larger disk storage, servers can
connect more than a handful of
computers on a network.
TYPES OF NETWORKS
LOCAL AREA NETWORK (LAN)
LOCAL AREA NETWORK (LAN)
Supplies networking capability to a group of computers in close proximity to each other such as in an office building, a school, or a home.
A LAN is useful for sharing resources like files, printers, games or other applications. A LAN in turn often connects to other LANs, and to the Internet or other WAN.
LOCAL AREA NETWORK (LAN)
Most local area networks are built with relatively inexpensive hardware such as Ethernet cables, network adapters, and hubs. Wireless LAN and other more advanced LAN hardware options also exist.
Specialized operating system software may be used to configure a local area network. For example, most flavors of Microsoft Windows provide a software package called Internet Connection Sharing (ICS) that supports controlled access to LAN resources.
LOCAL AREA NETWORK (LAN)
The term LAN party refers to a multiplayer gaming event where
participants bring their own computers
and build a temporary LAN.
METROPOLITAN AREA
NETWORK (MAN)
METROPOLITAN AREA
NETWORK (MAN)
A metropolitan area network (MAN) is a computer network that usually spans
a city or a large campus. A MAN
usually interconnects a number of
local area networks (LANs) using a
high-capacity backbone technology,
such as fiber-optical links, and
provides up-link services to wide area
networks (or WAN) and the Internet.
METROPOLITAN AREA
NETWORK (MAN) The IEEE 802-2002 standard describes a MAN
as being :
A MAN is optimized for a larger geographical area than a LAN, ranging from several blocks of buildings to entire cities. MANs can also depend on communications channels of moderate-to-high data rates. A MAN might be owned and operated by a single organization, but it usually will be used by many individuals and organizations. MANs might also be owned and operated as public utilities. They will often provide means for internetworking of local networks.
WIDE AREA NETWORK (WAN)
WIDE AREA NETWORK (WAN)
A wide area network (WAN) is a computer network that covers a broad area (i.e., any
network whose communications links cross
metropolitan, regional, or national boundaries).
This is in contrast with personal area networks (PANs), local area networks (LANs), campus
area networks (CANs), or metropolitan area
networks (MANs) which are usually limited to a
room, building, campus or specific metropolitan
area (e.g., a city) respectively.
LEARNING OUTCOME
Student should be able to:
1. Explain client, server, workstation,
network interface card, network
operating system, node, connectivity
device, backbone, segment, topology
and transmission media.
2. Distinguish the computer network
topologies : bus, ring, star and hybrid.
ELEMENT IN CLIENT-SERVER
NETWORKS
ELEMENT
Client
Server
Workstation
Network Interface Card
Network Operating System
Node Segment
Backbone
Connectivity Device
Topology
Transmission Media
ELEMENT IN CLIENT-SERVER
NETWORKS
Client
A computer on the network that request resources or services from another computer on a network.
Server
A computer on the network that manages shared resources among client.
ELEMENT IN CLIENT-SERVER
NETWORKS Workstation A computer on which a person performs
everyday regular assignments. A workstation is primarily a personal computer (PC). It can also be a laptop. Almost any modern PC can be used as a workstation and participate to a network.
Network Interface Card (NIC) The device inside the computer that
connect a computer to the network.
http://www.functionx.com/networking/Lesson02.htm
ELEMENT IN CLIENT-SERVER
NETWORKS Network Operating System (NOS)
The software that run on a server and enables the server to:
i. Manage data and other resources for a number of client.
ii. Ensure that only authorized users access the network.
iii. Control which type of files a user can open and read.
iv. Restrict when and from where users can access the network.
v. Dictate which rules computer to communicate.
vi. Supply application to clients.
A software that allows multiple computers to communicate, share files and hardware devices with one another.
Examples of network operating systems include Novell NetWare, Microsoft Windows NT, Microsoft Windows 2008 Server, Sun Solaris, Linux.
ELEMENT IN CLIENT-SERVER
NETWORKS
Node
A client, server or other device that can
communicate over the network and that is
identified by a unique number, known as its
network address.
Segment
A part of network. Usually a segment is
composed of a group of nodes that use the
same communications channel for all their
traffic.
ELEMENT IN CLIENT-SERVER
NETWORKS
Backbone
The part of a network (connection) to
which segments and shared devices
connect. A backbone is sometimes
referred to as a network of network because its role in interconnecting
smaller parts of LAN or WAN.
ELEMENT IN CLIENT-SERVER
NETWORKS Connectivity Device
A specialized device that allow multiple networks or multiple parts of the networks to connect and exchange data. Examples : repeater, hub/switch, bridges, router, gateways.
Topology
The physical layout of a computer networks.
Transmission Media
The means through which data is transmitted and received. Examples : coaxial cable, STP, UTP, fiber optic.
Network Topology
BUS
STAR
RING
HYBRID
BUS
Each node (workstation, server, switch and etc) is connected to a single cable.
A signal from the source travels in both directions to all machines connected on the bus cable until it finds the intended recipient.
If the machine address does not match the intended address for the data, the machine ignores the data.
BUS
Alternatively, if the data does match the machine address, the data is accepted.
Since the bus topology consists of only one wire, it is rather inexpensive to implement when compared to other topologies. However to manage this network topology require higher cost.
BUS
What is the advantages of this topology?
Easy to connect a computer or peripheral to a linear bus.
Requires less cable length than mesh or star topologies.
It is cheaper than any other topologies.
BUS
What happen is the single cable fail or damaged?
Additionally, since only one cable is utilized, it can be the single point of failure. If the network cable breaks, the entire network will be down.
BUS
Others disadvantages of this topology?
Terminators are required at both ends of the backbone cable.
Addition of new devices requires modification or replacement of the backbone.
The managing cost of network is too high.
STAR
Each network host is connected to a central hub or switch with a point-to-point connection.
All traffic that traverses the network passes through the central hub.
The hub acts as a signal repeater.
STAR
The star topology is considered the easiest topology to design and implement.
What is the advantages of this topology?
Easy to install and reconfigure.
No disruptions to the network when connecting or removing devices.
Easy to detect faults and to remove parts.
Robustness, that is, if one link fails, only that link is affected, other links remain active.
STAR
The star topology is considered the easiest topology to design and implement.
What is the advantage of this topology?
An advantage of the star topology is the simplicity of adding additional nodes.
STAR
What is the disadvantage if this topology?
The primary disadvantage of the star topology is that the hub represents a single point of failure.
Requires more cable length than a bus topology.
More expensive than bus topologies because of the cost of the hubs and etc.
RING
A network topology that is set up in a circular fashion in which data travels around the ring in one direction and each device on the right acts as a repeater to keep the signal strong as it travels.
RING
Each device incorporates a receiver for the incoming signal and a transmitter to send the data on to the next device in the ring. The network is dependent on the ability of the signal to travel around the ring.
http://www.datacottage.com/nch/troperation.htm
RING
What is the disadvantage of
this topology?
The failure of one machine will cause
the entire network
to fail.
http://wiki.answers.com/Q/Advantages_and_disadvantages_of_topologies
HYBRID
Hybrid networks use a combination of any two or more topologies in such a way that the resulting network does not exhibit one of the standard topologies (e.g., bus, star, ring, etc.).
HYBRID
A hybrid topology is always produced when two different basic network topologies are connected. Two common examples for Hybrid network are: star ring network and star bus network
HYBRID
Star Ring Network
Star Bus Network
HYBRID
Advantages of this topology?
Can be designed in many ways for various purposes.
Provides better result according to the management.
Disadvantages of this topology?
Difficult to identify the problem if entire system is down.
Learning Outcome
Student should be able to:
1. Identify organization that set standards for networking : ANSI, EIA, TIA, IEEE, ISO, ITU, ISOC, IANA, ICANN.
2. Explain source, channel and destinations.
3. Explain rules of communications.
4. Explain message encoding, formatting, size, timing and patterns.
Information Search
Form group of 3 students.
You will be entering Poster Competition about the standards for networking:
1. ANSI (American_National_Standards_Institute) fares | faeez
2. EIA/TIA (Electronic_Industries_Alliance / Telecommunications Industry Association) eynani | leow
3. IEEE anselm | farhan
4. ISO (International_Organization_for_Standardization) amirul hakim | az-syafiz
5. ITU (International_Telecommunication_Union) walid | syahmi
6. ISOC (Internet_Society) kugendran | fauzie
7. IANA (Internet_Assigned_Numbers_Authority) khumuthavalli
8. ICANN nur hanani
EXERCISE
1. Draw a diagram showing three computer and one printer connecting to each other using: a. Bus topology
b.Star topology
c. Ring topology
2. One computer wants to send file to printer. By using the diagram you created in question one, draw the data path/route taken by this file for the three topology mention above.
PRINCIPLES OF
COMMUNICATION
Channel A distinct communication path between
two or more nodes, much like a lane is a distinct transportation path on a freeway.
Channels may be separated either logically (as in multiplexing) or physically (as when they are carried by separate wires).
SOURCE DESTINATION
Channel
PRINCIPLES OF
COMMUNICATION
The sender (source) who creates the message to be transmitted
A medium that carries the message. (channel)
The receiver (sink) who receives the message. (destinations).
SOURCE DESTINATION
Channel
RULES OF COMMUNICATION
Establish a link Issue a command and command qualifier
Send, receive
Acknowledgment of command Acknowledgement field in Ethernet frame
Dissection messages Packet, frame
Error detection and correction cyclic redundancy check (CRC)
Termination of transmission
EXAMPLE
TERMINOLOGIES IN NETWORK
1. Message Encoding
Example: Specific Area Message Encoding or SAME is the protocol used to encode the Emergency Alert System (EAS) and NOAA Weather Radio in the U.S
2. Message Formatting
Example: ICMP message use in ping, tracert
3. Message Size
Example: Thus smtp2.example.com declares that it will accept a fixed maximum message size no larger than 14,680,064 octets
TERMINOLOGIES IN NETWORK
4. Message Timing
Example: ttl time to live
5. Message Patterns
A Message Exchange Pattern (MEP) describes the pattern of messages
required by a communications protocol to
establish or use a communication
channel.
Learning Outcome
Student should be able to:
1. Identify cards on expansion board inside a computer : PIC NIC, PIC Express NIC.
2. Identify cards installed to the computers bus externally : PCMCIA adapter, USB port, FireWire, Compact Flash NIC.
3. Identify On-board NIC.
4. Identify NIC.
NETWORK INTERFACE CARD
(NIC)
Various types of Network Interface Card :
1. Cards on an expansion board inside a computer (PCI NIC, PCI Express NIC)
2. Cards installed to the computers bus externally (PCMCIA adapter, USB port, Fire Wire, Compact Flash NIC)
3. On board NIC
4. Wireless NIC
NETWORK INTERFACE CARD
(NIC) A circuit board or chip, which allows the
computer to communicate to other computers on a Network for the purpose of sharing resources, information and computer hardware.
This board can be connected to a cable or other method of transferring data such as infra red.
Utilizing network cards to connect to a network allow users to share data such as companies being able to have the capability of having a database that can be accessed all at the same time, send and receive e-mail internally within the company, or share hardware devices such as printers.
PART OF NETWORK INTERFACE
CARD (NIC) CONNECTORS
Network cards have three main types of connectors. Below is an example of what a network card may look like.
BNC - As illustrated in the above picture, the BNC connector is a round connector which is used for Thinnet or 10Base-2 Local Area Network.
DB9 - DB9 connectors were commonly used before for serial peripheral devices like keyboards, mice, joysticks, etc.
In network it used in token ring topology network.
PART OF NETWORK INTERFACE
CARD (NIC)
RJ45 - Today, one of the most popular types of connections used with computer
networks. RJ45 looks similar to a phone
connector or RJ11 connector but is slightly
larger.
PART OF NETWORK INTERFACE
CARD (NIC)
LED -The LEDs indicates if it detects a network; generally by a green light
which may flash as it communicates,
and then a red light which indicates
collisions which will generally flash or
not flash at all.
TYPES OF NETWORK
INTERFACE CARD (NIC)
Installed on an expansion board inside a computer
PCI NIC
PCI Express NIC
TYPES OF NETWORK
INTERFACE CARD (NIC)
Cards installed to the computers bus externally
PCMCIA Adapter
USB Network Adapter
FireWire Network Adapter
Compact Flash NIC
PCMCIA - Personal Computer
Memory Card
International Association is an industry organization best know
for developing a standard network
adapter using the PC Card form factor.
The PC Card form factor was designed for thinness, and PCMCIA is therefore
especially well suited for notebook
computers. Most notebooks contain
two PCMCIA slots that hold one or two
of these cards.
USB NETWORK
ADAPTER
FIREWIRE NETWORK ADAPTER
Compact Flash NIC
TYPES OF NETWORK
INTERFACE CARD (NIC)
On-board NIC
TYPES OF NETWORK
INTERFACE CARD (NIC)
Wireless NIC
Wireless PCMCIA network adapter Wireless PCI network adapter
Wireless USB adapter
Wireless Compact Flash network adapter
LAN CONNECTIVITY
HARDWARE Repeater
An electronic device that receives a signal and retransmits it at a higher level and/or higher power, so that the signal can cover longer distances.
To regenerate the signal when the signal received is weak or interference, this device will make a copy of bits to bits by the original signal strength.
Repeaters work with the actual physical signal, and do not attempt to interpret the data being transmitted, they operate on the Physical Layer, the first layer of the OSI model.
LAN CONNECTIVITY
HARDWARE Hub
An Ethernet hub, active hub, network hub, repeater hub or hub is a device for connecting multiple twisted pair or fiber optic Ethernet devices together and making them act as a single network segment.
Hubs work at the Physical Layer (Layer 1) of the OSI model
Active Hub is called multiport repeater. participate in collision detection, forwarding
a jam signal to all ports if it detects a collision.
LAN CONNECTIVITY
HARDWARE
Switch A network switch or switching hub is a
computer networking device that connects network segments.
The term commonly refers to a network bridge that processes and routes data at the Data Link Layer (Layer 2) of the OSI model.
Switches that additionally process data at the Network Layer (Layer 3 and above) are often referred to as Layer 3 switches or multilayer switches.
LAN CONNECTIVITY
HARDWARE
Difference between Hub & Switch
A switch learns which devices are connected to its ports and then forwards
on packets to the appropriate port only.
Hubs repeat everything they receive and resulting unnecessary traffic being sent to
all devices on the network.
LAN CONNECTIVITY
HARDWARE
HUB SWITCH
Hub is broadcasting device. Switch is point to point
communication.
Hub operates at physical layer. Switch operate at data link
layer.
Hub is not an intelligent service
(dummy device).
Switch is intelligent device.
Hub simply broadcast the
incoming.
Switch uses switching table to
find the correct destination.
Hub cannot be used as repeater. Switch can be used as a
repeater.
LAN CONNECTIVITY
HARDWARE Bridges
A network bridge connects multiple network segments at the Data Link Layer (Layer 2) of the OSI model.
Used to transmit data between networks that using the same protocol.
A bridge and switch are very much alike; a switch being a bridge with numerous ports.
Bridges can analyze incoming data packets to determine if the bridge is able to send the given packet to another segment of the network
LAN CONNECTIVITY
HARDWARE Router
A device that forwards data packets along networks. A router is connected to at least two networks, commonly two LANs or WANs or a LAN and its ISPs network. Routers are also located at gateways, the places where two or more networks connect.
Makes decisions on how to manage the contents of the frame based on protocol and network address.
Routers use headers and forwarding tables to determine the best path for forwarding the packets, and they use protocols such as ICMP to communicate with each other and configure the best route between any two hosts.
LAN CONNECTIVITY
HARDWARE
Router
A router is a networking device whose software and hardware are customized to
the tasks of routing and forwarding
information.
A router has two or more network interfaces, which may be to different
physical types of network (such as copper
cables, fiber, or wireless) or different
network standards
Works in Layer 3 OSI model
LAN CONNECTIVITY
HARDWARE
Gateway
A network gateway is an internetworking system capable of joining together two
networks that use different base protocols.
A network gateway can be implemented completely in software, completely in
hardware, or as a combination of both.
Depending on the types of protocols they support, network gateways can operate at
any level of the OSI model.
LAN CONNECTIVITY
HARDWARE Gateway
Connect two systems using different formatting, communications protocols, or architecture Repackage information to be read by another
system
Operates at multiple OSI Model layers
E-mail gateway Internet gateway LAN gateway Voice/data gateway Firewall
Learning Outcome
Student should be able to:
1. Install and configure NIC hardware
and software.
2. Illustrate repeater, hub/switch,
bridges, routers, gateways.
Learning Outcome
Student should be able to:
1. Build simple peer-to-peer network using TIA/EIA-568-A or TIA/EIA-568-B wiring standard.
2. Build simple LAN using two hosts and a switch.
3. Build network drive to share a file.
4. Assemble and configure a network printer in a simple LAN
http://en.wikipedia.org/wiki/American_National_Standards_Institute
http://en.wikipedia.org/wiki/Electronic_Industries_Alliance http://en.wikipedia.org/wiki/Telecommunications_Industry_Ass
ociation
http://en.wikipedia.org/wiki/Ieee http://en.wikipedia.org/wiki/International_Organization_for_Sta
ndardization
http://en.wikipedia.org/wiki/International_Telecommunication_Union
http://en.wikipedia.org/wiki/Internet_Society http://en.wikipedia.org/wiki/Internet_Assigned_Numbers_Auth
ority
http://en.wikipedia.org/wiki/Icann