Ans: 192.168.1.106, 63583
The sequence number of the TCP SYN segment is 0 since it is used to imitate the TCP connection between the client computer and gaia.cs.umass.edu.
According to below figure, in the Flags section, the Syn flag is set to 1 which indicates that this segment is a SYN segment.
The value of the acknowledgement field in the SYNACK segment is 1. The value of the ACK field in the SYNACK segment is determined by the server gaia.cs.umass.edu. The server adds 1 to the initial sequence number of SYN segment form the client computer. For this case, the initial sequence number of SYN segment from the client computer is 0, thus the value of the ACK field in the SYNACK segment is 1.
1
Segment 1 sequence number is 1
Segment 2 sequence number is 579
Segment 3 sequence number is 416
Segment 4 sequence number is 1164
Segment 5 sequence number is 3252
Segment 6 sequence number is 5000
Sent Time ACK Time RTT
05.003220 05.229284 0.226064
05.003582 05.246693 0.243111
05.003582 05.255980 0.252398
05.003582 05.269617 0.266035
05.003582 05.280389 0.276807
05.003582 05.294617 0.291035
ERTTt1 = SRTTs1 = 0.226064
ERTTt2 = 0.875 ∗ ERTTt1 + 0.125 ∗ SRTTs2
= 0.875 * 0.226064 + 0.125 * 0.243111
= 0.22819488
ERTTt3 = 0.875 ∗ ERTTt2 + 0.125 ∗ SRTTs3
= 0.875 * 0.22819488 + 0.125 * 0.252398
= 0.23122027
ERTTt4 = 0.875 ∗ ERTTt3 + 0.125 ∗ SRTTs4
= 0.875 * 0.23122027 + 0.125 * 0.266035
= 0.23557211
ERTTt5 = 0.875 ∗ ERTTt4 + 0.125 ∗ SRTTs5
= 0.875 * 0.23557211 + 0.125 * 0.276807
= 0.24072647
ERTTt6 = 0.875 ∗ ERTTt5 + 0.125 ∗ SRTTs6
= 0.875 * 0.24072647 + 0.125 * 0.291035
= 0.24701504
707, 1400, 1400, 1400, 1400, 1400
4-7 What is the minimum amount of available buffer space advertised at the received for the entire trace? Does the lack of receiver buffer space ever throttle the sender?
No, the seq num never drop
next seq no = prev seq no. + ack size
ACK ACK Sequence Number Acknowledged data
1 708 707
2 2108 1400
3 3508 1400
4 4908 1400
5 6308 1400
6 7708 1400
data: 153829-1 = 153828 bytes
time:06.618555-05.003220 = 1.615335 sec
throughput = 153828/1.615335 = 95.22978241 KB/s