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Topic 1 · Network architectures
Topic 2 · Application protocols
Read captures
Interpret real DNS and HTTP traffic captures, as in Wireshark.Draw DNS sequences
Write, in order, the DNS messages that are exchanged.DNS cache
Count messages and servers, say what the local server stores and work out TTLs in consecutive queries from two hosts.Draw HTTP sequences
Draw HTTP connections and messages: cache, proxy, cookies and timings.Recognise HTTP exchanges
Choose, among four timelines, the one that matches what the cache holds and what has changed on the server.Topic 3 · Transport layer
rdt protocols
Look at an rdt2.0, 2.1, 2.2 or 3.0 exchange like the ones from class and say what happens with a packet with errors, a duplicate or a loss.GBN and SR
With several pipelined packets and some losses: what the receiver does, what the sender retransmits and how much is transmitted with Go-Back-N and with Selective Repeat.Draw TCP sequences
Draw, tick by tick, the TCP segments: SN, AN, flags, window, delayed ACKs and losses.Questions about TCP diagrams
Look at a fragment of a TCP exchange that is already drawn: predict the next segment, fill in what is missing or explain why it is sent.Save your progress
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