2020-03-14 21:53:36 +00:00
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__ __ __
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__/ // /_/ /___ _____ ____ _ __ ___ ____ __
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/_ _ __/ / __ `/ __ \/ __ `/ / / / / | /| / / / / /
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/_ _ __/ / /_/ / / / / /_/ / / /_/ /| |/ |/ / /_/ /
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/_//_/ /_/\__,_/_/ /_/\__, / \__,_/ |__/|__/\__,_/
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/____/
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## High level approach
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2020-03-14 22:17:54 +00:00
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For this assignment we developed a new protocol that would be particularly efficient at
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transferring a file over an unreliable connection. The protocol devides the input file
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into fixed-length "segments", numbers them sequentially, and attempts to transfer them to
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the receiver. It repeatedly retransmits segments that it is not confident that the
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receiever has obtained. The receiever periodically sends batched-acknowledgements that
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list receieved segments. The segments are compressed using state-of-the-art compression
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algorithms to ensure expedient delivery. The rate of sending and acknowledgement is
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continuously tuned to optimize for network conditions.
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2020-03-14 21:53:36 +00:00
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## Challenges
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2020-03-14 22:17:54 +00:00
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We faced many challenges implementing this protocol, such as the following:
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- Learning how to use cutting-edge event-loop libraries in Rust
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- Selecting a re-transmission algorithms that would be resistant to drops and duplicates
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- Choosing constants that would tune the transmission rate to adjust automatically to
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network latency and bandwidth
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- Ensuring that *both* connections would close once the file had been successfully
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transferred.
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2020-03-14 21:53:36 +00:00
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## Testing
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2020-03-14 22:17:54 +00:00
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Various internal algorithms and datastructures were tested using simple unit tests. For
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instance, we have unit tests to check that our packet encoding/decoding schemes work
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correctly.
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However, testing general consistency of the protocol was done by running the scripts
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provided to us, which automatically adjust network conditions and send large files.
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