CCNAHelp.Com
Archives

7 layer OSI Model

The Transport Layer

:

There comes a point when the client decides to severe its connection with the server because it has finished its transaction and has no need for it, could be the other way round also wherein the server decides to terminate its connection with the client. Whatever be the case the initiator of the termination would send a FIN packet (FIN stands for finish you don't have to be a genius to guess it).

Once the receiver gets the FIN packet it would send an FIN+ACK packet to the sender and the sender would send an ACK in reply and once this three way communication takes place both the entities severe their session and free up their resources for future sessions.

I don't want to split hairs now but consider a case when FIN packet fails to reach the other end due to congestion i.e. the FIN packet is dropped along the path. In this case since the initiator doesn't receive the FIN+ACK packet from the other end it would keep resending the FIN packet till it receives a FIN+ACK, in the worst case it would have to severe the session once the TCP session times out in which case the entities would severe their sessions and free up the resources for future sessions.

So we have come the full circle, the details covered were as mentioned below

  • connection initiation through 3 way handshake

  • data transfer

  • congestion control

  • connection termination

    • Next we will discuss about UDP




    Continue to : Layer 3: IP addressing explained
    Home   |   Advertise   |   Mail   |   Contact Form   |   Legal Notice  |   Useful Resources

    Copyrights © 2006, CCNAhelp.com