Exercises

Exercises

20.1

In Figure 20.6 we could have shown a byte numbered 0 and a byte numbered 8193. What do these 2 bytes designate ?

20.2

Look ahead to Figure 22.1 and explain the setting of the PUSH flag by the host bsdi.

20.3

In a Usenet posting someone complained about a throughput of 120,000 bits/sec on a 256,000 bits/sec link with a 128-ms delay between the United States and Japan (47% utilization), and a throughput of 33,000 bits/sec when the link was routed over a satellite (13% utilization). What does the window size appear to be for both cases? (Assume a 500-ms delay for the satellite link.) How big should the window be for the satellite link?

20.4

If the API provided a way for a sending application to tell its TCP to turn on the PUSH flag, and a way for the receiver to tell if the PUSH flag was on in a received segment, could the flag then be used as a record marker?

20.5

In Figure 20.3 why aren't segments 15 and 16 combined?

20.6

In Figure 20.13 we assume that the ACKs come back nicely spaced , corresponding to the spacing of the data segments. What happens if the ACKs are queued somewhere on the return path , causing a bunch of them to arrive at the same time at the sender?



TCP.IP Illustrated, Volume 1. The Protocols
TCP/IP Illustrated, Vol. 1: The Protocols (Addison-Wesley Professional Computing Series)
ISBN: 0201633469
EAN: 2147483647
Year: 1993
Pages: 378

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