To provide some additional context on this, there are two main goals here. First, sharing the other side's real-time perspective on network state can be useful in choosing application-level behavior (e.g. ABR). Second, recalling data from a previous connection can be useful with transport-level optimizations such as Careful Resume (https://datatracker.ietf.org/doc/html/draft-ietf-tsvwg-careful-resume-24). It is already possible for the server to embed this recall data in Address Validation tokens, but that's opaque to clients and there's overlap with data that the client might wish to consume.
This extension enables each side to share network information with the peer over the course of the connection, optionally having some of the values passed back to it on a future connection. Since the peer (generally the client, but that's not a requirement) can inspect the information, it can make a more informed choice about whether it wants to echo back the prior state or start fresh for privacy reasons. Chairs, might this have a few minutes in As Time Permits? -Mike Bishop (no hat) ________________________________ From: 袁靖昊 <[email protected]> Sent: Sunday, October 19, 2025 10:47 AM To: [email protected] <[email protected]> Subject: New ID--Exchanging Congestion Control Data in QUIC Hello colleagues at QUIC WG. I'm Yuan Jinghao from ByteDance, and I'd like to introduce to you a draft we recently submitted. We have noticed that in various scenarios, there is a demand to represent and consume congestion control status. Based on this, we have constructed a custom QUIC frame, which is composed of multiple Network Statistics. Every "Network Statistics" records network signals such as bandwidth, packet loss, and RTT, etc. This extension allows peers to exchange their cc status and enables the original data to be echoed back to the source in a secure form. We have applied the prototype of this draft in live streaming for several years and achieved actual QoE benefits. We hope that this extension can not only be applied in TikTok live but also receive professional evaluations and guidance from the industry. Thanks, Jinghao Yuan draft-00: https://datatracker.ietf.org/doc/draft-yuan-quic-congestion-data/
