Computer Networks Quiz 2: 23 November 2025 (September 2025 term)

During the fast recovery, a TCP connection has:

$CWND = 8 \text{ MSS}$

$\text{Inflight} = 4 \text{ MSS}$

Each duplicate ACK increases CWND by 1 MSS.

If 4 duplicate ACKs are received before a new ACK arrives, what will be the value of CWND just before the new ACK, and what will it be value after the new ACK arrives (when CWND and inflight realign)?

A packet with destination IP 128.20.15.7 arrives at a router. The router's forwarding table has the following entries:

Which output port will the router select?

A TCP receiver has a buffer size of 30 KB. The sender transmits data at 10 KB/s, while the receiver’s application reads data from the buffer at 6 KB/s. Assuming the buffer is initially empty, after how many seconds will the receiver buffer become full ?
Note: Give your answer to two decimal places.