what is the diffrence between TCP TAHOE and TCP RENO

Question

what is the diffrence between TCP TAHOE and TCP RENO.

what I want to know is about the behivor to 3-dup-ack and timeout?

what happend to cwind what happend to SST?

thanks!

Jeana

Answer 1

TCP Tahoe and Reno are two forms of handling TCP congestion controls specifically when it comes to receiving 3 duplicate acks.

Tahoe: handles 3 duplicate acks similar (exactly?) to receiving a timeout. It first performs a fast retransmit. Then, it halves the ssthresh value to original congestion window size, and sets the new window size to 1 and staying in slow start.

Reno: The successor to Tahoe, goes into fast recovery mode upon receiving three duplicate acks thereby halving the ssthresh value. For each successive duplicate acks (fourth, fifth, sixth), cwind increases by 1. Once the receiver finally receives the missing packet, TCP will move to congestion avoidance or slowstate upon a timeout.

Source: TCP congestion control - TCP Tahoe and Reno

Appreciate