TCP-RELIABLE TRANSPORT SERVICE

INTRODUCTION:

 TCP is the major transport protocol architecture in the TCP/IP suite. It uses unreliable datagram function offered by IP when sending data to another system. It gives reliable data delivery function to applications.

TRANSMISSION CONTROL PROTOCOL:

 Reliability is the major responsibility of the Transport layer. In TCP/IP, TCP gives reliable transport service. Most Internet programs use TCP as no other protocol has proved to do better.

SERVICE PROVIDED BY TCP:

 Following are the services given by TCP:

• Connection-oriented service
• Point-to-point
• Complete reliability
• Full-duplex communication
• Stream interface
• Reliable connection startup
• Graceful connection shutdown

END-TO-END SERVICE AND DATAGRAMS:

 Applications may request a connection. TCP connections are known Virtual Connections. They are prepared by software only. Internet does not give software or hardware support for the connections. TCP software modules on two computers give an illusion of a connection.

 TCP uses IP to take on messages. TCP message is attached in IP datagram and transmit to the destination. On the receiver host, IP passes the texts to TCP. It is given in the figure below.

ACHIEVING RELIABILITY:

 The main problems in the reliable delivery are:

• Unreliable delivery by the underlying interaction system.
• System reboot.