Markdown Version | Session Recording

Session Date/Time: 23 Jul 2024 20:00

tcpm

Summary

The TCPM working group meeting covered several key topics including the status of current drafts, updates on PRR and accurate ECN, a presentation on the TCP Act Rate Request option, and a discussion regarding a mitigation for the GoStuck problem. The meeting involved discussions on milestones, potential implementations of drafts on Quick, and feedback on existing implementations.

Key Discussion Points

• Milestones: The working group discussed whether to keep, update, or remove dates from the milestones. Several opinions were expressed, ranging from finding dates helpful for tracking progress to considering them unrealistic and potentially misleading. A compromise was proposed to focus on the sequence of document delivery rather than specific dates.
• PRR: Neil presented updates on the Proportional Rate Reduction draft, addressing comments received, especially from Mark. Key changes included clarification on peer triggers, initialization of the recover FS variable, specification of delivery data, and setting the congestion window to SS Thresh.
• PRR and Quick: The possibility of implementing PRR for Quick was discussed, leading to a discussion on whether a new document was needed or if the current PRR document should be updated with a section on Quick.
• Accurate ECN: Mirja channeled an update on the Accurate ECN document. A key issue discussed was the lack of consideration for the send path in relation to TCP Segmentation Offload (TSO). There was a strong consensus that the document was ready for publication given its importance for L4S deployment.
• TCP Act Rate Request (TAR): Carla presented updates on the TAR option, addressing concerns about potential negative impacts of TAR on network elements that modify act rates. The proposed solution involves the sender reverting to normal delayed act operation upon retransmission timer expiration.
• GoStuck Mitigation: Yerba Pan presented on a mitigation for the GoStuck problem, focusing on ACN number validation for established TCP connections. Two implementation choices were presented, and the status of implementations in Linux and FreeBSD were discussed.

Decisions and Action Items

• PRR:
  • Alessandro and Ian volunteered to investigate adding text to the PRR draft regarding Quick implementation within a two month timeframe.
  • The working group tentatively agreed to ship the document to the IESG.
• Accurate ECN:
  • Ship the Accurate ECN document to the IESG with a caveat described by the shepherd.
• GoStuck Mitigation:
  • The working group will send out a call for adoption for the GoStuck mitigation draft to the mailing list.
  • Michael volunteered to help create an RFC.

Next Steps

• PRR:
  • Alessandro and Ian will provide text or feedback regarding the applicability of the PRR document to Quick.
  • The chairs will evaluate the added quick text.
  • A second WGLC will be conducted if the quick text is added.
  • Ship to IESG.
• Accurate ECN:
  • The shepherd write up for Accurate ECN document will be completed, and the document will be shipped to the IESG with the agreed-upon caveat.
• GoStuck Mitigation:
  • A call for adoption will be sent to the mailing list.
  • If adopted, the working group will produce a short RFC.