49 lines
2 KiB
Markdown
49 lines
2 KiB
Markdown
# Project 3: reliable transport
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## What is what
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| File | Role |
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| :--- | :--- |
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| `gbn.py` | yours: `Sender.send()`; the receiver is given |
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| `sr.py` | yours: `Sender.send()` and `Receiver.receive()` |
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| `stopwait.py` | given: stop-and-wait, with the timer, cumulative ACKs and the FIN/FINACK close |
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| `packet.py` | given: packet format, Internet checksum, MSS 1000 |
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| `channel.py` | given: simulated link for the offline checks |
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| `selfcheck.py` | given: public checks over that link |
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| `transfer.py` | given: file transfer over UDP |
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| `experiments.py` | given: loss and window sweeps, writes `results.json` |
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| `challenge.py` | given: client for the class challenge server |
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| `PROTOCOL.md` | given: the challenge control exchange |
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The grader restores every given file from a clean copy, so leave them as they are.
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## Run
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Python 3, standard library only.
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```text
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python3 selfcheck.py # both protocols
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python3 selfcheck.py gbn # one side
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python3 experiments.py # both sweeps
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python3 experiments.py loss # loss sweep only
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python3 experiments.py window # window sweep only
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python3 challenge.py B-gbn --student your_id
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```
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A side that is still unwritten prints SKIP after about 30 seconds per check, so run one side at a time while you write code.
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The experiments need `ip netns` and `tc netem`. In the course container:
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```text
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docker run --rm --privileged -v "$PWD/..":/work -w /work/starter cs4220-net
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python3 experiments.py
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```
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The challenge client needs the class server: run it on your own machine, or in the container without `--network none`. We host no local peer.
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## Tool references
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- [Python socket module](https://docs.python.org/3/library/socket.html)
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- [ip-netns](https://man7.org/linux/man-pages/man8/ip-netns.8.html)
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- [tc-netem](https://man7.org/linux/man-pages/man8/tc-netem.8.html)
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- [Course container help](../../../labs/tools/course-container.canvas.html) and [docker run](https://docs.docker.com/reference/cli/docker/container/run/)
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