Session Date/Time: 27 Mar 2023 06:30

tcpm

Summary

The TCPM working group meeting covered several draft updates, including those related to ECN, TCP-RR, and a new proposal for aggregated TCP options. Discussions focused on implementation status, addressing review comments, and potential deployment challenges. The group also considered whether specific drafts were ready for working group last call and explored potential security implications of new proposals.

Key Discussion Points

ECN Updates (Accurate ECN and Generalized ECN): Status of implementation, addressing review comments from Gary, Marco, and others. Considered whether to move text related to a specific edge case (Ax Pure x) to the ECN+ draft due to its relevance only when ECN+ is enabled. Gary's review regarding proxies, offload, and other boxes, focusing on clarifying the roles of the data sender, receiver, host, client, and server. Concerns regarding the impact of Act x on fast retransmit and other TCP mechanisms.
TCP Read Request (TCP-RR): Updates based on feedback, including concerns about "stretch acks" and their impact on congestion window opening, send bursts, and RTT estimation. Suggestions were made to use pacing to mitigate send bursts and to avoid producing stretch acks during slow start.
Service Update Based Application: Presentation of a draft proposing a mechanism for fast service pass handover. Raised concerns about security vulnerabilities, particularly the potential for connection hijacking. Discussed whether TCP was the appropriate layer for this functionality.
Aggregated Option for TCP Space Extension: Presentation of a draft proposing a new TCP option to aggregate smaller options, aiming to reduce header overhead. Discussed deployment strategies and potential benefits. Consideration of a profile option that includes sets of other options, allowing for future extensions to existing configurations.

Decisions and Action Items

Accurate ECN: Authors to incorporate feedback from Gary and Marco. Authors to address concerns about Ax Pure x and consider moving relevant text to the ECN+ draft. Authors to explicitly mention that this is experimental.
Generalized ECN: The chairs will consider running Working Group Last Call after remaining comments are dealt with.
TCP Read Request: Authors to incorporate feedback on pacing and stretch acks, especially the need for more data to validate the performance impact of proposed solutions. Authors to reconsider adding the text regarding window size limits. Authors to think more about how to prevent performance degradation after a timeout.
Service Update Based Application: Authors to further investigate security concerns and consider alternative approaches, potentially at a different layer.
Aggregated Option for TCP Space Extension: Author to consider the benefits of including more common options, like MSS and window scale, in the aggregated option. Author to discuss possible security issues with the chairs.

Next Steps

Authors of various drafts to incorporate feedback and address action items.
The chairs to evaluate draft readiness for working group last call.
Further discussion on the mailing list for unresolved issues, particularly concerning security and deployment challenges.