Hi Martin,
To repeat my statement from the TSVWG room: There was a question if the mentioned socket options allow the sending of IP CE marked packets from the host. This is an important question warranting documentation, especially as e.g. the Accurate ECN draft has explicit wording that the sender should validate the path's capabilites, including the unmodified delivery of CE-marked packets. As Michael Tuexen pointed out, this may depend on the setting of global host settings (sysctl), but if similar testing/validation mechanisms are to be implemented on non-kernel transport protocols, knowning the capabilities is certainly required. Best regards, Richard Am 24.08.2024 um 02:39 schrieb Martin Duke:
Hi TSVWG and QUIC, I've made it some of the way through implementing receive ECN for Chromium, which involved quite a bit of trial and error in figuring out the quirks of the Apple and Windows UDP socket APIs. This is an informational draft that tries to capture some of that learning, since hopefully more QUIC implementations will add ECN support across multiple platforms. Obviously, this is a work in progress. People that have worked with other OSes, or that can see into the kernel code and update/correct/refute some of my statements here, are welcome to contribute. My guess is that it fits into TSVWG, although it is mostly of relevance to QUIC folks. If people are really interested in it, we could adopt it TSVWG. If not, at least there's a record somewhere so that others don't have to suffer as I did. Martin ---------- Forwarded message --------- From: <[email protected] <mailto:[email protected]>> Date: Fri, Aug 23, 2024 at 12:33 PM Subject: New Version Notification for draft-duke-tsvwg-udp-ecn-00.txt To: Martin Duke <[email protected] <mailto:[email protected]>> A new version of Internet-Draft draft-duke-tsvwg-udp-ecn-00.txt has been successfully submitted by Martin Duke and posted to the IETF repository. Name: draft-duke-tsvwg-udp-ecn Revision: 00 Title: Configuring UDP Sockets for ECN for Common Platforms Date: 2024-08-23 Group: Individual Submission Pages: 9 URL: https://www.ietf.org/archive/id/draft-duke-tsvwg-udp-ecn-00.txt <https://www.ietf.org/archive/id/draft-duke-tsvwg-udp-ecn-00.txt> Status: https://datatracker.ietf.org/doc/draft-duke-tsvwg-udp-ecn/ <https://datatracker.ietf.org/doc/draft-duke-tsvwg-udp-ecn/> HTMLized: https://datatracker.ietf.org/doc/html/draft-duke-tsvwg-udp-ecn <https://datatracker.ietf.org/doc/html/draft-duke-tsvwg-udp-ecn> Abstract: Explicit Congestion Notification (ECN) applies to all transport protocols in principle. However, it had limited applications for UDP until QUIC became widely deployed. As a result, documentation of UDP socket APIs for ECN on various platforms is sparse. This document records the results of experimenting with these APIs in order to get ECN working on UDP for Chromium on Apple, Linux, and Windows platforms. The IETF Secretariat
