TCP-IP - Information Technology - Lecture Slides, Slides of Information Technology

Download TCP-IP - Information Technology - Lecture Slides and more Slides Information Technology in PDF only on Docsity!

Introductionto TCP-IP

INTRODUCTION • TCP stands^ for^ Transmission

Control Protocol^ and^ IP

stands^ for^ Internet Protocol. • The TCP/IP is a set of protocols thatdefines how the transmissions take placeas well as exchanged across the internet. • It is very effective and popular set ofprotocols.

-^ A TCP/IP internet operates like a single networkconnecting many computers of any size and type. •^ The TCP/IP was developed before OSI and it ismade up of only four layers named as:OSI^

TCP/IP Application^

Application Presentation^

Not Present SessionTransport^

Transport Network^

Internet Data link^

Host to host Physical

-^ A network in TCP/IP internetworkcan be LAN, WAN or MAN. •^ The^ data^

on^ the^ network

is

transported^

in^ packets^

called

datagrams. • A^ datagrams^

carries^ information

sufficient^ for^

routing^ from^

the

originating^ source

machine^ to^

the

destination^

machine^ without

establishing a connection.

ADDRESSING • When an application wants to set up aconnection to other application it needsaddress of that. • Whether it^ is^ a^ connection

oriented service^ or^ connection

less^ TCP/IP,^ it needs^ the^ address

of^ source^ and destination points.

-^ Addressing can be studied in threebroad^ categories

in^ TCP/IP^

as

follows:1.Physical addressing2.Logical addressing3.IP addressing.

-^ It is a unique identifier for a specificmode on network. •^ The physical address is specified byswitches or jumpers on the networkinterface card. •^ The^ format^

of^ physical^

address

depends^ upon^

to^ particular type

of

network. • For example in an Ethernet LAN a 48bit physical address is used.

-^ Three types of physical addresses are:1.Unicast address2.Multicast address3.Broadcast address1.Unicast^ address

are^ permanently

assigned^ to^ the

network^ interface

card^ (NIC)^ and

are^ unique^ for

a

machine.

LOGICAL ADDRESSING • To^ provide^ a^ unique

identifier^ for^

a specific node on a network by the networkoperating^ system

is^ called^

logical addressing. • The network operating system establisheslogical addresses for different nodes on thenetwork. • Normally while sending messages to anynode on the network, the host only knowsthe logical address of target computer.

docsity.com

-^ The host has to find the physical address ofthe node and for that TCP/IP uses a specialprotocol^ named

as^ address^ resolution protocol (ARP). • ARP allows^ a^ host

of^ find the physical address of node on the same network whenit only knows the targets logical address. • The^ network^ interface

card^ contains^

a table, known as address resolution cache,that^ maps^ logical

addresses^ to^

the hardware^ addresses

of^ the^ node^ on

the network.

docsity.com

-^ Thereafter its physical address is found bythe host using ARP and then only therequired data message can be conveyed tothe destination node. •^ Thus logical addresses are one that definea logical topology to reach a particularhost. •^ In terms of networks the logical addressescontain^ network

number,^ subnet

work numbers,^ super^

network^ number,

host number etc.

-^ However these numbers are assignedby the network operating system tothem, but to reach them the physicaladdress^ is^

required^ which

is

calculated using some method usingthe logical number specified in thedatagram.

-^ These addresses identify the connectionof a host to its network. •^ Thus the IP packet header contains an IPnetwork address for the sender and IPnetwork address for the destination. •^ These IP network addresses are said tobe logical because they are defined interms^ of^ the^

logical^ topology

of^ the

routers and hosts.

-^ Each host in the internet has a globallyunique IP address. •^ IP address uniquely identify a host onnetwork. •^ The^ IP^ address

format^ apparently contains three fields1.Class type2.Network – ID3.Host - ID