Today, behaviour is decided based on if transport sequence number v2 is in the SDP answer. But it might be better to decide based on received packets since it is valid to negotiate both extensions. Another bonus With this solution is that Call does not need to know about receive header exensions. This is an alternative to https://webrtc-review.googlesource.com/c/src/+/291337 Bug: webrtc:7135 Change-Id: Ib75474127d6e2e2029557b8bb2528eaac66979f8 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/291525 Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Reviewed-by: Johannes Kron <kron@webrtc.org> Commit-Queue: Per Kjellander <perkj@webrtc.org> Cr-Commit-Position: refs/heads/main@{#39226}