Networked Life: 20 Questions and Answers by Mung Chiang Capter 14. Can you answer the exercise 14.3?

14.3 TCP Reno congestion window **

Remember the size of the bottleneck window during the phase avoiding congestion of TCP Reno, changes over time as below.

If an ACK is omitted, then increase w from 1/w.

If congestion is detected, reduce w from w/2.

Let's assume that the probability of a transmission failure is p, the probability of one

successful transmission is then 1 - p. The transmission rate is x = w/RTT packets per second.

(a) Write the equation for the expected change w per time step.

(b) In equilibrium, the expected change is 0. Using (a) indicates that

r, = 1-12(1-2) RITV P