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Introduction to LAN,MAN

and WAN

LAN(Local Area Network)

MAN(Metropolitan Area Network)

WAN(Wide Area Network)

Network classification by size or scale

A local area network (LAN) is privately owned network that operates in a very small geographical area upto few kilometers.

It is used to link devices in a single office, building or a campus.

The resources to be shared can be a hardware device like printer, software like an application program or data.

The various devices in LAN are connected to central devices called hub or switch using a cable.

Local Area Networks (LANs):

LAN offers high speed communication of data.

LAN is easy to and maintain.

The communication medium used in LAN is co-axial cable, unshielded twisted pair.

LAN operates on principle of the broadcasting.

Client

Client Client

Client Client

Client

The Local Network (LAN)

-Most LANs use fixed wiring although increasingly Wireless connectivity (a WLAN) is becoming common.-The major advantage of a WLAN is that there does not need to be a ‘hard-wired’ connection between the computers. This allows users’ computers to easily join and leave the network, and move around. Normally the computers communicate via an access point’ that is permanently connected to a standard fixed network.

Wireless LAN

A Typical WLAN

• developed by Xerox in 1973–1975

• standardized as IEEE 802.3

• has replaced token ring, FDDI and ARCNET

• usually uses twisted pair cable ( RJ-45)

ETHERNET

Ethernet Standard10BaseT

10Mbps (Mega bits per second)100BaseT

100Mbps1000BaseT

1000Mbps or 1Gbps

A MAN normally consists of a group of LANs, which may be spread across an area the size of a city.

It would normally consist of a number of buildings each with a central hub that connects to the MAN network.

Older MANs use broadcast technologies but as switching has become more efficient point to point relay is now more typical and the boundary between MAN and WAN is now becoming unclear.

Metropolitan Area Network (MAN)

MANs are increasingly using the same access technology as LANs. The links are typically made using microwave, radio, infra-red free-space or optical-fiber links.

WAN covers a large geographic area such as country, continent or even whole of the world.

WAN interconnects two or more LANs(or WANs) and provide long distance transmission of data, images, audio and video information.

may be public, leased or private

Also called “enterprise networks” if they are privately owned by a large company.

Wide Area Network(WAN)

Transmission media include microwave, fibre-optic, telephone lines & satellite.Is typically slower and less reliable than a LAN.Services include internet ,frame relay and ATM(Asynchronous Transfer Mode).The largest and most well-known example of a WAN is the Internet

DIFFERENCE BETWEEN LAN,MAN,WAN

BASIS LAN MAN WAN

Full form Local area network

Metropolitan area network

Wide area network

Geographical span

Operates in small area such as same building or campus.

Operates in large area such as city.

Operates over large area such as country or continent.

Ownership Usually privately owned

Privately or public owned

Usually public owned

BASIS LAN MAN WAN

Setup cost Very cheap Moderate cost

Very costly

Error rate Very low moderate High

Transmission media

Is usually wires such as coaxial cable or UTP

Can be wires or telephone lines

Because of long distance medium can be PSTN or satellite

speed high Moderate Low

Internet working devices

Hub, switch, bridge, repeater

Router, gateways

Router, gatways

BASIS LAN MAN WAN

Example LAN is used in offices or in college campus

MAN is used scale telephone service and cable TV in a city.

WAN is used for internet-working i.e. internet.

It is a set of rules or protocol that governs the transfer of hypertext between two or more computers. The hypertext transfer protocol (http) is a protocol used mainly to access data on the World Wide Web. HTTP functions as a combination of FTP and SMTP.

HTTP: THE HYPERTEXT TRANSFER PROTOCOL

HTTP uses the services of TCP on port 80.The basic operation consists of three steps:1) the client opens a TCP connection and sends

request for a document.2) The server respond with the document.3) The server closes the connection. HTTP transaction between the client and server

consists of request and response. HTTP messages from the client to server are called

HTTP request. HTTP messages from the server to client HTTP

response.

HTTP transaction

HTTP request and response messages

The request line Header Body

Status line Header Body

HTTP request message

HTTP response message

The request line:- it is consists of three elements: methods or request type, URL, HTTP version.Status line:-it is also consists of three elements: HTTP version, status code, status phrase.

HTTP request message:-The request type portion of request line in HTTP request message specifies the various methods.

HTTP response message:-These are status codes of status line in response message

Status codes (continued)

Request header:- The header present in HTTP request message is called request header. Each header has a header name, a colon, a space and a header value.

Various request headers

Various Response headers

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