a wide area network

8/2/2019 A Wide Area Network

1/16

GURU NANAK KHALSA

COLLEGE

CLASS : T.Y.BFM


2/16

Project On

WIDE AREA NETWORK(WAN)

Under the Guidance Of Miss Smita. A

- GROUP MEMBERS

JIGAR GALA

13

RUSHAB

HARIA 17

NIHUL JAIN

20

JAY MEHTA

29


3/16

PRATIK

SINGH 46

ACKOWLEDGEMENT

My sincere thanks to MISS SMITA .Awho offered excellent

support, advice and guidance throughout the project without

which this project would have been incomplete.

I would also like to thank all my professors who shaped my

talent and my abilities throughout my BFM course. Would

like to thanks college principal Dr. Ajit singh, Head of

Department Allan Dsouza.

Not to forget my parents who supported me and was a

source of inspiration.


4/16

SIGNATURE

OF TEACHER

INDEX

CONTENT

1. Introduction

2. Options

2.1. Circuit Switching

2.2. Paket Switching

2.3. Call Relay


5/16

WIDE AREA NETWORK

A wide area network (WAN) is a telecommunication network that

covers a broad area (i.e., any network that links across metropolitan,

regional, or national boundaries). Business and government entities

utilize WANs to relay data among employees, clients, buyers, andsuppliers from various geographical locations. In essence this mode of

telecommunication allows a business to effectively carry out its daily

function regardless of location.[1]

This is in contrast withpersonal area networks (PANs), local area

networks (LANs), campus area networks (CANs), ormetropolitan

area networks (MANs) which are usually limited to a room, building,

campus or specific metropolitan area (e.g., a city) respectively.

The textbook definition of a WAN is a computer network spanning regions,

countries, or even the world. However, in terms of the application of computer

networking protocols and concepts, it may be best to view WANs as computer

networking technologies used to transmit data over long distances, and between

different LANs, MANs and other localised computer networking architectures.

This distinction stems from the fact that common LAN technologies operating

at Layer 1/2 (such as the forms of Ethernet or Wifi) are often geared towards

physically localised networks, and thus cannot transmit data over tens, hundreds

or even thousands of miles or kilometres.
http://en.wikipedia.org/wiki/Wide_area_network#cite_note-0http://en.wikipedia.org/wiki/Personal_area_networkhttp://en.wikipedia.org/wiki/Local_area_networkhttp://en.wikipedia.org/wiki/Local_area_networkhttp://en.wikipedia.org/wiki/Campus_area_networkhttp://en.wikipedia.org/wiki/Metropolitan_area_networkhttp://en.wikipedia.org/wiki/Metropolitan_area_networkhttp://en.wikipedia.org/wiki/Wide_area_network#cite_note-0http://en.wikipedia.org/wiki/Personal_area_networkhttp://en.wikipedia.org/wiki/Local_area_networkhttp://en.wikipedia.org/wiki/Local_area_networkhttp://en.wikipedia.org/wiki/Campus_area_networkhttp://en.wikipedia.org/wiki/Metropolitan_area_networkhttp://en.wikipedia.org/wiki/Metropolitan_area_network


6/16

WANs necessarily do not just connect physically disparate LANs. A CAN, for

example, may have a localised backbone of a WAN technology, which connects

different LANs within a campus. This could be to facilitate higher bandwidth

applications, or provide better functionality for users in the CAN.

WANs are used to connect LANs and other types of networks together, so that

users and computers in one location can communicate with users and computers

in other locations. Many WANs are built for one particular organization and are

private. Others, built by Internet service providers, provide connections from an

organization's LAN to the Internet. WANs are often built using leased lines. At

each end of the leased line, a routerconnects the LAN on one side with a

second routerwithin the LAN on the other. Leased lines can be very expensive.

Instead of using leased lines, WANs can also be built using less costly circuit

switching orpacket switching methods. Networkprotocols including TCP/IPdeliver transport and addressing functions. Protocols including Packet over

SONET/SDH, MPLS, ATM and Frame relay are often used by service

providers to deliver the links that are used in WANs. X.25 was an important

early WAN protocol, and is often considered to be the "grandfather" of Frame

Relay as many of the underlying protocols and functions ofX.25 are still in use

today (with upgrades) by Frame Relay.

Academic research into wide area networks can be broken down into three

areas: mathematical models, network emulation and network simulation.

Performance improvements are sometimes delivered via wide area file services

orWAN optimization.
http://en.wikipedia.org/wiki/Internet_service_providerhttp://en.wikipedia.org/wiki/Leased_linehttp://en.wikipedia.org/wiki/Router_(computing)http://en.wikipedia.org/wiki/Router_(computing)http://en.wikipedia.org/wiki/Circuit_switchinghttp://en.wikipedia.org/wiki/Circuit_switchinghttp://en.wikipedia.org/wiki/Packet_switchinghttp://en.wikipedia.org/wiki/Communications_protocolhttp://en.wikipedia.org/wiki/TCP/IPhttp://en.wikipedia.org/wiki/Packet_over_SONET/SDHhttp://en.wikipedia.org/wiki/Packet_over_SONET/SDHhttp://en.wikipedia.org/wiki/Multiprotocol_Label_Switchinghttp://en.wikipedia.org/wiki/Asynchronous_Transfer_Modehttp://en.wikipedia.org/wiki/Frame_relayhttp://en.wikipedia.org/wiki/X.25http://en.wikipedia.org/wiki/X.25http://en.wikipedia.org/wiki/Mathematical_modelhttp://en.wikipedia.org/wiki/Network_emulationhttp://en.wikipedia.org/wiki/Network_simulationhttp://en.wikipedia.org/wiki/Wide_area_file_serviceshttp://en.wikipedia.org/wiki/WAN_optimizationhttp://en.wikipedia.org/wiki/Internet_service_providerhttp://en.wikipedia.org/wiki/Leased_linehttp://en.wikipedia.org/wiki/Router_(computing)http://en.wikipedia.org/wiki/Router_(computing)http://en.wikipedia.org/wiki/Circuit_switchinghttp://en.wikipedia.org/wiki/Circuit_switchinghttp://en.wikipedia.org/wiki/Packet_switchinghttp://en.wikipedia.org/wiki/Communications_protocolhttp://en.wikipedia.org/wiki/TCP/IPhttp://en.wikipedia.org/wiki/Packet_over_SONET/SDHhttp://en.wikipedia.org/wiki/Packet_over_SONET/SDHhttp://en.wikipedia.org/wiki/Multiprotocol_Label_Switchinghttp://en.wikipedia.org/wiki/Asynchronous_Transfer_Modehttp://en.wikipedia.org/wiki/Frame_relayhttp://en.wikipedia.org/wiki/X.25http://en.wikipedia.org/wiki/X.25http://en.wikipedia.org/wiki/Mathematical_modelhttp://en.wikipedia.org/wiki/Network_emulationhttp://en.wikipedia.org/wiki/Network_simulationhttp://en.wikipedia.org/wiki/Wide_area_file_serviceshttp://en.wikipedia.org/wiki/WAN_optimization


7/16

OPTIONS

Options

Descriptions Advantages

Disadvantages

Bandwith-

Range

SampleProtocol

UsedLeasedline

Point-to-Pointconnection betweentwo computers orLocal Area Networks(LANs)

Mostsecure

Expensive PPP, HDLC,SDLC, HNAS

Circuitswitching

A dedicated circuitpath is createdbetween end points.Best example is dialupconnections

LessExpensive

Call Setup 28 - 144kbit/s

PPP, ISDN

Packetswitching

Devices transportpackets via a sharedsingle point-to-point orpoint-to-multipoint linkacross a carrierinternetwork. Variablelength packets aretransmitted overPermanent VirtualCircuits (PVC) or

Switched VirtualCircuits (SVC)

Sharedmediaacross link

X.25Frame-Relay
http://en.wikipedia.org/wiki/Leased_linehttp://en.wikipedia.org/wiki/Leased_linehttp://en.wikipedia.org/wiki/Point-to-Point_Protocolhttp://en.wikipedia.org/wiki/HDLChttp://en.wikipedia.org/wiki/Synchronous_Data_Link_Controlhttp://en.wikipedia.org/w/index.php?title=HNAS&action=edit&redlink=1http://en.wikipedia.org/wiki/Circuit_switchinghttp://en.wikipedia.org/wiki/Circuit_switchinghttp://en.wikipedia.org/wiki/Circuit_switchinghttp://en.wikipedia.org/wiki/Dialuphttp://en.wikipedia.org/wiki/Point-to-Point_Protocolhttp://en.wikipedia.org/wiki/ISDNhttp://en.wikipedia.org/wiki/Packet_switchinghttp://en.wikipedia.org/wiki/Packet_switchinghttp://en.wikipedia.org/wiki/Packet_switchinghttp://en.wikipedia.org/wiki/Permanent_virtual_circuithttp://en.wikipedia.org/wiki/Switched_virtual_circuithttp://en.wikipedia.org/wiki/X.25http://en.wikipedia.org/wiki/Frame-Relayhttp://en.wikipedia.org/wiki/Frame-Relayhttp://en.wikipedia.org/wiki/Leased_linehttp://en.wikipedia.org/wiki/Leased_linehttp://en.wikipedia.org/wiki/Point-to-Point_Protocolhttp://en.wikipedia.org/wiki/HDLChttp://en.wikipedia.org/wiki/Synchronous_Data_Link_Controlhttp://en.wikipedia.org/w/index.php?title=HNAS&action=edit&redlink=1http://en.wikipedia.org/wiki/Circuit_switchinghttp://en.wikipedia.org/wiki/Circuit_switchinghttp://en.wikipedia.org/wiki/Circuit_switchinghttp://en.wikipedia.org/wiki/Dialuphttp://en.wikipedia.org/wiki/Point-to-Point_Protocolhttp://en.wikipedia.org/wiki/ISDNhttp://en.wikipedia.org/wiki/Packet_switchinghttp://en.wikipedia.org/wiki/Packet_switchinghttp://en.wikipedia.org/wiki/Packet_switchinghttp://en.wikipedia.org/wiki/Permanent_virtual_circuithttp://en.wikipedia.org/wiki/Switched_virtual_circuithttp://en.wikipedia.org/wiki/X.25http://en.wikipedia.org/wiki/Frame-Relayhttp://en.wikipedia.org/wiki/Frame-Relay


8/16

Cellrelay

Similar to packetswitching, but usesfixed length cellsinstead of variablelength packets. Data

is divided into fixed-length cells and thentransported acrossvirtual circuits

Best forsimultaneous useof voiceand data

Overheadcan beconsiderable

ATM

Transmission rates usually range from 1200 bit/s to 24 Mbit/s, although some

connections such as ATM and Leased lines can reach speeds greater than 156

Mbit/s. Typical communication links used in WANs are telephone lines,microwave links & satellite channels.

Recently with the proliferation of low cost ofInternet connectivity many

companies and organizations have turned to VPN to interconnect their

networks, creating a WAN in that way. Companies such as Cisco, New Edge

Networks and Check Point offer solutions to create VPN networks.

Circuit Switching

Circuit switching is a methodology of implementing a telecommunications

networkin which two network nodes establish a dedicated communications

channel (circuit) through the network before the nodes may communicate. The

circuit guarantees the full bandwidth of the channel and remains connected for

the duration of the communication session. The circuit functions as if the nodes

were physically connected as with an electrical circuit.

The defining example of a circuit-switched network is the early analogtelephone network. When a call is made from one telephone to another,

switches within the telephone exchanges create a continuous wire circuit

between the two telephones, for as long as the call lasts.

Circuit switching contrasts withpacket switching which divides the data to be

transmitted intopackets transmitted through the network independently. Packet

switching shares available network bandwidth between multiple communication

sessions.
http://en.wikipedia.org/wiki/Cell_relayhttp://en.wikipedia.org/wiki/Cell_relayhttp://en.wikipedia.org/wiki/Overheadhttp://en.wikipedia.org/wiki/Asynchronous_Transfer_Modehttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/VPNhttp://en.wikipedia.org/wiki/Ciscohttp://en.wikipedia.org/wiki/Check_Pointhttp://en.wikipedia.org/wiki/Telecommunications_networkhttp://en.wikipedia.org/wiki/Telecommunications_networkhttp://en.wikipedia.org/wiki/Network_nodeshttp://en.wikipedia.org/wiki/Communications_channelhttp://en.wikipedia.org/wiki/Communications_channelhttp://en.wikipedia.org/wiki/Telecommunication_circuithttp://en.wikipedia.org/wiki/Telephone_networkhttp://en.wikipedia.org/wiki/Telephone_exchangehttp://en.wikipedia.org/wiki/Packet_switchinghttp://en.wikipedia.org/wiki/Network_packethttp://en.wikipedia.org/wiki/Cell_relayhttp://en.wikipedia.org/wiki/Cell_relayhttp://en.wikipedia.org/wiki/Overheadhttp://en.wikipedia.org/wiki/Asynchronous_Transfer_Modehttp://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/VPNhttp://en.wikipedia.org/wiki/Ciscohttp://en.wikipedia.org/wiki/Check_Pointhttp://en.wikipedia.org/wiki/Telecommunications_networkhttp://en.wikipedia.org/wiki/Telecommunications_networkhttp://en.wikipedia.org/wiki/Network_nodeshttp://en.wikipedia.org/wiki/Communications_channelhttp://en.wikipedia.org/wiki/Communications_channelhttp://en.wikipedia.org/wiki/Telecommunication_circuithttp://en.wikipedia.org/wiki/Telephone_networkhttp://en.wikipedia.org/wiki/Telephone_exchangehttp://en.wikipedia.org/wiki/Packet_switchinghttp://en.wikipedia.org/wiki/Network_packet


9/16

In circuit switching, the bit delay is constant during a connection, as opposed to

packet switching, where packet queues may cause varyingpacket transfer delay.

Each circuit cannot be used by other callers until the circuit is released and a

new connection is set up. Even if no actual communication is taking place, the

channel remains unavailable to other users. Channels that are available for newcalls are said to be idle.

Virtual circuit switching is apacket switching technology that emulates circuit

switching, in the sense that the connection is established before any packets are

transferred, and packets are delivered in order.

While circuit switching is commonly used for connecting voice circuits, the

concept of a dedicated path persisting between two communicating parties or

nodes can be extended to signal content other than voice. Its advantage is that it

provides for continuous transfer without the overhead associated withpacketsmaking maximal use of available bandwidth for that communication. The

disadvantage is inflexibility; the connection and the bandwidth associated with

it are reserved and unavailable for other uses.

Examples of circuit-switched networks

public switched telephone network(PSTN)

ISDN B-channel

Circuit Switched Data (CSD) and High-Speed Circuit-Switched Data

(HSCSD) service in cellular systems such as GSM

Datakit

X.21 (Used in the German DATEX-L and Scandinavian DATEX circuit

switched data network)

optical mesh network
http://en.wikipedia.org/wiki/Packet_transfer_delayhttp://en.wikipedia.org/wiki/Virtual_circuit_switchinghttp://en.wikipedia.org/wiki/Packet_switchinghttp://en.wikipedia.org/wiki/Network_packethttp://en.wikipedia.org/wiki/Public_switched_telephone_networkhttp://en.wikipedia.org/wiki/ISDNhttp://en.wikipedia.org/wiki/Circuit_Switched_Datahttp://en.wikipedia.org/wiki/High-Speed_Circuit-Switched_Datahttp://en.wikipedia.org/wiki/GSMhttp://en.wikipedia.org/wiki/Datakithttp://en.wikipedia.org/wiki/X.21http://en.wikipedia.org/w/index.php?title=DATEX-L&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=DATEX&action=edit&redlink=1http://en.wikipedia.org/wiki/Optical_mesh_networkhttp://en.wikipedia.org/wiki/Packet_transfer_delayhttp://en.wikipedia.org/wiki/Virtual_circuit_switchinghttp://en.wikipedia.org/wiki/Packet_switchinghttp://en.wikipedia.org/wiki/Network_packethttp://en.wikipedia.org/wiki/Public_switched_telephone_networkhttp://en.wikipedia.org/wiki/ISDNhttp://en.wikipedia.org/wiki/Circuit_Switched_Datahttp://en.wikipedia.org/wiki/High-Speed_Circuit-Switched_Datahttp://en.wikipedia.org/wiki/GSMhttp://en.wikipedia.org/wiki/Datakithttp://en.wikipedia.org/wiki/X.21http://en.wikipedia.org/w/index.php?title=DATEX-L&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=DATEX&action=edit&redlink=1http://en.wikipedia.org/wiki/Optical_mesh_network


10/16

PACKET SWITCHING

Packet switching is a digital networking communications method that groups all

transmitted data regardless of content, type, or structure into suitably sized

blocks, called packets. Packet switching features delivery of variable-bit-rate

data streams (sequences of packets) over a shared network. When traversingnetwork adapters, switches, routers and othernetwork nodes, packets are

buffered and queued, resulting in variable delay and throughput depending on

the traffic load in the network.

Packet switching contrasts with another principal networking paradigm, circuit

switching, a method which sets up a limited number of dedicated connections of

constant bit rate and constant delay between nodes for exclusive use during the

communication session. In case of traffic fees (as opposed to flat rate), for

example in cellular communication services, circuit switching is characterized

by a fee per time unit of connection time, even when no data is transferred,

while packet switching is characterized by a fee per unit of information.

Two major packet switching modes exist; (1) connectionless packet switching,

also known as datagram switching, and (2) connection-oriented packet

switching, also known as virtual circuit switching. In the first case each packet

includes complete addressing or routing information. The packets are routed

individually, sometimes resulting in different paths and out-of-order delivery. In

the second case a connection is defined and preallocated in each involved node

during a connection phase before any packet is transferred. The packets include
http://en.wikipedia.org/wiki/Network_packethttp://en.wikipedia.org/wiki/Network_nodehttp://en.wikipedia.org/wiki/Throughputhttp://en.wikipedia.org/wiki/Circuit_switchinghttp://en.wikipedia.org/wiki/Circuit_switchinghttp://en.wikipedia.org/wiki/Cellular_communicationhttp://en.wikipedia.org/wiki/Connectionless_communicationhttp://en.wikipedia.org/wiki/Datagramhttp://en.wikipedia.org/wiki/Connection-oriented_communicationhttp://en.wikipedia.org/wiki/Virtual_circuithttp://en.wikipedia.org/wiki/Network_packethttp://en.wikipedia.org/wiki/Network_nodehttp://en.wikipedia.org/wiki/Throughputhttp://en.wikipedia.org/wiki/Circuit_switchinghttp://en.wikipedia.org/wiki/Circuit_switchinghttp://en.wikipedia.org/wiki/Cellular_communicationhttp://en.wikipedia.org/wiki/Connectionless_communicationhttp://en.wikipedia.org/wiki/Datagramhttp://en.wikipedia.org/wiki/Connection-oriented_communicationhttp://en.wikipedia.org/wiki/Virtual_circuit


11/16

a connection identifier rather than address information, and are delivered in

order.

Packet mode communication may be utilized with or without intermediate

forwarding nodes (packet switches orrouters). In all packet modecommunication, network resources are managed by statistical multiplexing or

dynamic bandwidth allocation in which a communication channel is effectively

divided into an arbitrary number of logical variable-bit-rate channels or data

streams. Statistical multiplexing, packet switching and otherstore-and-forward

buffering introduces varying latency and throughput in the transmission. Each

logical stream consists of a sequence of packets, which normally are forwarded

by the multiplexers and intermediate network nodes asynchronously using first-

in, first-out buffering. Alternatively, the packets may be forwarded according to

some scheduling discipline forfair queuing, traffic shaping or for differentiatedor guaranteed quality of service, such as weighted fair queuing orleaky bucket.

In case of a shared physical medium, the packets may be delivered according to

some packet-mode multiple access scheme.

Cell relay

In computer networking, cell relay refers to a method ofstatistically multiplexing small

fixed-lengthpackets, called "cells", to transport data between computers or kinds of network

equipment. It is an unreliable,connection-orientedpacket switched data communications

protocol.

Cell relay transmission rates usually are between 56 kbit/s and several gigabits per second.

ATM, a particularly popular form of cell relay, is most commonly used for home DSL

connections, which often runs between 128 kbit/s and 1.544 Mbit/s (DS1), and for high-speed

backbone connections (OC-3 and faster).

Cell relay protocols have neitherflow control norerror correction capability, are information-

content independent, and correspond only to layers one and two of the OSI Reference Model.

Cell relay can be used for delay- and jitter-sensitive traffic such as voice and video.

Cell relay systems break variable-length user packets into groups of fixed-length cells, that

add addressing and verification information. Frame length is fixed in networking hardware,

based on time delay and user packet-length considerations. One user data message may be

segmented over many cells.

Cell relay statems may also carry bitstream-based data such as PDH traffic, by breaking it

into streams of cells, with a lightweight synchronization and clock recovery shim. Thus cell

relay systems may potentially carry any combination of stream-based and packet-based data.

This is a form ofstatistical time division multiplexing.
http://en.wikipedia.org/wiki/Router_(computing)http://en.wikipedia.org/wiki/Statistical_multiplexinghttp://en.wikipedia.org/wiki/Dynamic_bandwidth_allocationhttp://en.wikipedia.org/wiki/Communication_channelhttp://en.wikipedia.org/wiki/Store-and-forwardhttp://en.wikipedia.org/wiki/Throughputhttp://en.wikipedia.org/wiki/FIFO_(computing)http://en.wikipedia.org/wiki/FIFO_(computing)http://en.wikipedia.org/wiki/Fair_queuinghttp://en.wikipedia.org/wiki/Traffic_shapinghttp://en.wikipedia.org/wiki/Quality_of_servicehttp://en.wikipedia.org/wiki/Weighted_fair_queuinghttp://en.wikipedia.org/wiki/Leaky_buckethttp://en.wikipedia.org/wiki/Multiple_accesshttp://en.wikipedia.org/wiki/Computer_networkhttp://en.wikipedia.org/wiki/Statistical_multiplexinghttp://en.wikipedia.org/wiki/Packet_(information_technology)http://en.wikipedia.org/wiki/Reliability_(computer_networking)http://en.wikipedia.org/wiki/Connection-orientedhttp://en.wikipedia.org/wiki/Packet_switchinghttp://en.wikipedia.org/wiki/Communications_protocolhttp://en.wikipedia.org/wiki/Communications_protocolhttp://en.wikipedia.org/wiki/Transmission_ratehttp://en.wikipedia.org/wiki/Kbit/shttp://en.wikipedia.org/wiki/Gigabits_per_secondhttp://en.wikipedia.org/wiki/Asynchronous_Transfer_Modehttp://en.wikipedia.org/wiki/Digital_Subscriber_Linehttp://en.wikipedia.org/wiki/Mbit/shttp://en.wikipedia.org/wiki/Digital_Signal_1http://en.wikipedia.org/wiki/OC-3http://en.wikipedia.org/wiki/Flow_controlhttp://en.wikipedia.org/wiki/Error_correctionhttp://en.wikipedia.org/wiki/Open_Systems_Interconnection--Reference_Modelhttp://en.wikipedia.org/wiki/Frame_(telecommunications)http://en.wikipedia.org/wiki/Networking_hardwarehttp://en.wikipedia.org/wiki/Plesiochronous_Digital_Hierarchyhttp://en.wikipedia.org/wiki/Statistical_time_division_multiplexinghttp://en.wikipedia.org/wiki/Router_(computing)http://en.wikipedia.org/wiki/Statistical_multiplexinghttp://en.wikipedia.org/wiki/Dynamic_bandwidth_allocationhttp://en.wikipedia.org/wiki/Communication_channelhttp://en.wikipedia.org/wiki/Store-and-forwardhttp://en.wikipedia.org/wiki/Throughputhttp://en.wikipedia.org/wiki/FIFO_(computing)http://en.wikipedia.org/wiki/FIFO_(computing)http://en.wikipedia.org/wiki/Fair_queuinghttp://en.wikipedia.org/wiki/Traffic_shapinghttp://en.wikipedia.org/wiki/Quality_of_servicehttp://en.wikipedia.org/wiki/Weighted_fair_queuinghttp://en.wikipedia.org/wiki/Leaky_buckethttp://en.wikipedia.org/wiki/Multiple_accesshttp://en.wikipedia.org/wiki/Computer_networkhttp://en.wikipedia.org/wiki/Statistical_multiplexinghttp://en.wikipedia.org/wiki/Packet_(information_technology)http://en.wikipedia.org/wiki/Reliability_(computer_networking)http://en.wikipedia.org/wiki/Connection-orientedhttp://en.wikipedia.org/wiki/Packet_switchinghttp://en.wikipedia.org/wiki/Communications_protocolhttp://en.wikipedia.org/wiki/Communications_protocolhttp://en.wikipedia.org/wiki/Transmission_ratehttp://en.wikipedia.org/wiki/Kbit/shttp://en.wikipedia.org/wiki/Gigabits_per_secondhttp://en.wikipedia.org/wiki/Asynchronous_Transfer_Modehttp://en.wikipedia.org/wiki/Digital_Subscriber_Linehttp://en.wikipedia.org/wiki/Mbit/shttp://en.wikipedia.org/wiki/Digital_Signal_1http://en.wikipedia.org/wiki/OC-3http://en.wikipedia.org/wiki/Flow_controlhttp://en.wikipedia.org/wiki/Error_correctionhttp://en.wikipedia.org/wiki/Open_Systems_Interconnection--Reference_Modelhttp://en.wikipedia.org/wiki/Frame_(telecommunications)http://en.wikipedia.org/wiki/Networking_hardwarehttp://en.wikipedia.org/wiki/Plesiochronous_Digital_Hierarchyhttp://en.wikipedia.org/wiki/Statistical_time_division_multiplexing


12/16

Cell relay is an implementation offast packet-switching technology that is used in

connection-oriented broadband integrated services digital networks (B-ISDN, and its better-

known supporting technology ATM) and connectionless IEEE 802.6 switched multi-megabit

data service (SMDS).

At any time there is information to be transmitted; the switch basically sends the data units.Connections dont have to be negotiated like circuit switching. Channels dont have to be

allocated because channels do not exist in ATM, and on condition that there is an adequate

amount of bandwidth to maintain it, there can be indefinite transmissions over the same

facility.

Cell relay utilizes data cells of a persistent size. Frames are comparable to data packets;

however they contrast from cells in that they may fluctuate in size based on circumstances.

This type of technology is not secure for the reason that its procedures do not support error

handling or data recovery. Per se, all delicate and significant transmissions may perhaps be

transported faster via fixed-sized cells, which are simpler to transmit compared to variable-

sized frames or packets.

Cell relay is extremely reliable for transporting vital data. Switching devices give the precise

method to cells as each endpoint address embedded in a cell. An example of cell relay is

ATM, a prevalent form utilized to transfer a cell with a fixed size of 53 bytes.

Label switching

Label switchingis a technique ofnetworkrelaying to overcome the problems

perceived by traditional IP-table switching (also known as traditional layer 3

hop-by-hop routing[1]). Here, the switching of networkpackets occurs at a lower

level, namely the data link layerrather than the traditional network layer.

Each packet is assigned a label number and the switching takes place after

examination of the label assigned to each packet. The switching is much faster

than IP-routing. New technologies such as Multiprotocol Label Switching

(MPLS) use label switching. The established ATM protocol also uses label

switching at its core.

According to RFC 2475 (An Architecture for Differentiated Services, December

1998): "Examples of the label switching (or virtual circuit) model include

Frame Relay, ATM, and MPLS. In this model path forwarding state and traffic

management orQuality of Service (QoS) state is established for traffic streams

on each hop along a network path. Traffic aggregates of varying granularity are

associated with a label switched path at an ingress node, and packets/cells

within each label switched path are marked with a forwarding label that is used

to look up the next-hop node, the per-hop forwarding behavior, and the

replacement label at each hop. This model permits finer granularity resourceallocation to traffic streams, since label values are not globally significant but
http://en.wikipedia.org/wiki/Fast_packet_switchinghttp://en.wikipedia.org/wiki/B-ISDNhttp://en.wikipedia.org/wiki/IEEE_802.6http://en.wikipedia.org/wiki/SMDShttp://en.wikipedia.org/wiki/Computer_networkhttp://en.wikipedia.org/wiki/Internet_protocolhttp://en.wikipedia.org/wiki/Label_Switching#cite_note-0http://en.wikipedia.org/wiki/Packet_(information_technology)http://en.wikipedia.org/wiki/OSI_protocolshttp://en.wikipedia.org/wiki/Data_link_layerhttp://en.wikipedia.org/wiki/Network_layerhttp://en.wikipedia.org/wiki/Routinghttp://en.wikipedia.org/wiki/Multiprotocol_Label_Switchinghttp://en.wikipedia.org/wiki/Asynchronous_Transfer_Modehttp://tools.ietf.org/html/rfc2475http://en.wikipedia.org/wiki/Quality_of_Servicehttp://en.wikipedia.org/wiki/Fast_packet_switchinghttp://en.wikipedia.org/wiki/B-ISDNhttp://en.wikipedia.org/wiki/IEEE_802.6http://en.wikipedia.org/wiki/SMDShttp://en.wikipedia.org/wiki/Computer_networkhttp://en.wikipedia.org/wiki/Internet_protocolhttp://en.wikipedia.org/wiki/Label_Switching#cite_note-0http://en.wikipedia.org/wiki/Packet_(information_technology)http://en.wikipedia.org/wiki/OSI_protocolshttp://en.wikipedia.org/wiki/Data_link_layerhttp://en.wikipedia.org/wiki/Network_layerhttp://en.wikipedia.org/wiki/Routinghttp://en.wikipedia.org/wiki/Multiprotocol_Label_Switchinghttp://en.wikipedia.org/wiki/Asynchronous_Transfer_Modehttp://tools.ietf.org/html/rfc2475http://en.wikipedia.org/wiki/Quality_of_Service


13/16

are only significant on a single link; therefore resources can be reserved for the

aggregate of packets/cells received on a link with a particular label, and the

label switching semantics govern the next-hop selection, allowing a traffic

stream to follow a specially engineered path through the network."

SOME OF THE IMAGES OF WAN


14/16


15/16

BIBLOGRAPHY

(1)http://www.nirmalbang.com/home.aspx

(2) http://en.wikipedia.org/wiki/wan/home.aspx

(3) http://en.wikipedia.org/wiki/wan
http://www.nirmalbang.com/mutual-funds/mutual-fund-http://www.nirmalbang.com/mutual-funds/mutual-fund-http://www.nirmalbang.com/mutual-funds/mutual-fund-


16/16

THANK

YOU

a wide area network

Documents