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RFC · TransportStandard explained

RFC 793: TCP: Reliable data streams over IP

Summary

RFC 793 defines TCP as an ordered, reliable and bidirectional byte stream between endpoints. RFC 793 was superseded by RFC 9293. TCP separates the reliability of transport from the unreliability of individual network paths.

Ideas

  • Sequence numbers order bytes and detect losses.
  • Acknowledgements and retransmissions create reliability.
  • Flow control protects slow receivers from overload.

Insights

  • The byte stream abstracts packet boundaries and simplifies applications.

Facts

  • RFC 793 was superseded by RFC 9293.

Remarks

  • RFC 793 has the status “Internet Standard”; current errata and successor documents should also be checked.

Recommendations

  • Take current TCP extensions and security fixes into account.
  • Measure loss, RTT and window sizes separately when troubleshooting performance.

References

Read the RFC at the RFC Editor

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RFC · 2021

RFC 9000: QUIC: Secure transport over UDP

RFC 9000 defines QUIC with encrypted connections, multiple streams and path migration on top of UDP. Transport innovation can be rolled out over UDP without waiting for operating system kernels. Encrypted control data improves privacy and makes network diagnostics harder.

RFC · 2001

RFC 3168: ECN: Signalling congestion without packet loss

RFC 3168 lets routers mark congestion in IP packets before queues have to drop packets. Packet loss is an expensive congestion signal and not strictly necessary. Cooperative endpoints can significantly reduce latency under load.