id. 03 tcp ip model

THE TCP/IP MODEL

يت ـــ ويا ثولن كـــ

ز

ياد هـــكو

ـ ـــةك ي يكى

اـــ ي ي ـــة ـــتـــ قــ ال

ـــةد هــــــــــكوــ ــ ــ جامعــ

Saleem Ibraheem - 2015 Akre Technical College

1 Duhok Polytechnic University

The TCP/IP is a set of protocols used on computer networks, mainly on the Internet. It provides an end-to-end connectivity by specifying how data should be packetized, addressed, transmitted, routed and received on a TCP/IP network.The TCP/IP was developed by a community of researchers centered around the ARPAnet.This model organized in to four layers and each protocol in the suite isresides in a particular layer.These layers are:

- Application Layer- Transport Layer- Network (Internet) Layer- Link Layer

ID. 03 IT-ATC.blogspot.com :: fb.com/ATC.Information.Technology :: fb.com/groups/IT.ATC

Figure 1 TCP/IP and OSI model


ز

ياد هـــكو







Network (Internet)LayerAt the Network layer, the TCP/IP supports the Internetworking Protocol (IP), in turn, uses four protocols(ARP, RARP, ICMP, and IGMP) for supporting data movement in this layer.


ز

ياد هـــكو






Internetworking Protocol (IP)

The Internetworking Protocol (IP) is the transmission mechanism used by the TCP/IP protocols. It is an unreliable and connectionless protocol, means that IP provides no error checking or tracking.

IP transports data in packets called datagrams, each of which is transported separately. Datagrams can travel along different routes and can arrive out of sequence or be duplicated.


Address Resolution Protocol

The Address Resolution Protocol (ARP) is used to find the physical address of

the node when its Internet address (Logical address) is known.


ز

ياد هـــكو






Reverse Address Resolution Protocol

The Reverse Address Resolution Protocol (RARP) allows a host to discover its

Internet address when it knows only its physical address. It is used when a

computer is connected to a network for the first time.


Internet Control Message Protocol


ز

ياد هـــكو






The Internet Control Message Protocol (ICMP) is a mechanism used by hosts

and gateways to send notification of datagram problems back to the sender.

ICMP sends query and error reporting messages.

Internet Group Message Protocol

The Internet Group Message Protocol (IGMP) is used to facilitate the

simultaneous transmission of a message to a group of recipients.


Transport Layer

At the transport layer, TCP/IP defines three protocols: Transmission Control

Protocol (TCP), User Datagram Protocol (UDP), and Stream Control

Transmission Protocol (SCTP).


ز

ياد هـــكو






IP is a host-to-host delivery packet protocol.While the UDP and TCP are

transport protocols responsible for delivery of a message from a process to

another process.

The SCTP is a new transport layer protocol, has been devised to meet the

needs of some newer applications.


User Datagram Protocol

The User Datagram Protocol (UDP) is a process-to-process protocol for data

delivery from the source to the destination that does not provide the service of

dividing a message into packets (datagrams) and reassembling it at the other

end; and also does not offer error recovery services.

Figure 2 UDP Datagram Format


ز

ياد هـــكو







Transmission Control Protocol


ز

ياد هـــكو






The Transmission Control Protocol (TCP) is a reliable stream transport

protocol.The term reliable stream, in this context, means connection-oriented:

A connection must be established between both ends of a transmission before

data transmitted.

At the sending end of each transmission,TCP divides a stream of data into

smaller units called segments. Each segment includes a sequence number for

reordering after receipt, together with an acknowledgment number for

the segments received.

At the receiving end,TCP collects each datagram as it comes in and reorders

the transmission based on sequence numbers.


Figure 3 TCP Segment Format


ز

ياد هـــكو







Stream Control Transmission Protocol

The Stream Control Transmission Protocol (SCTP) provides support for newer

applications such as voice over the Internet. It is a transport layer protocol that

combines the best features of UDP and TCP.


ز

ياد هـــكو





10

Duhok Polytechnic University


Application Layer


ز

ياد هـــكو





11

Duhok Polytechnic University

The application layer in TCP/IP is equivalent to the combined session, presentation, and application.This define the rules when implementing specific network applications.

The typical protocols used in the Application Layer:• FTP – File Transfer Protocol

•For file transfer• Telnet – Remote terminal protocol

•For remote login on any other computer on the network• SMTP – Simple Mail Transfer Protocol

•For mail transfer• HTTP – Hypertext Transfer Protocol

•For Web browsing
