0

I am doing some exam revision and i have a question regarding TCP/IP. I am OK with the first part on how TCP handles packet loss but not sure about the second part where the response is incorrect in the physical layer.

a) An assumption inherent in the TCP protocol is that lost acknowledgements(ACKs) are caused by congestion in the network. Explain how TCP responds to lost acknowledgements and discuss why this response is incorrect when the physical layer is implemented as a wireless carrier. Briefly discuss the consequences of this situation.

James Ferry
  • 127
  • 1
  • 3
  • 12
  • I've posted an answer for you, but this really isn't the type of question that belongs on Stack Overflow. Also, I would question the basis of the question itself; retransmitting a lost ACK is always appropriate, regardless fo the physical layer. – David Hoelzer Jan 02 '18 at 16:24

1 Answers1

1

Lost TCP acknowledgements end up being retransmitted when the acknowledgement timer in the sender elapses. This causes the sender to retransmit the data, resulting in the receiver generating another ACK.

In other words, since the ACK doesn't arrive from the recipient, it is the sender who initiates the retransmission, assuming that the data must not have arrived since there is no ACK within the retransmission window.

David Hoelzer
  • 15,862
  • 4
  • 48
  • 67