When the transport is terminated, if an error has occured, it will be propagated to the channels. When such errors can happen at the SCTP level (e.g. out of resources), RTCError may contain an error code matching the definition at https://www.iana.org/assignments/sctp-parameters/sctp-parameters.xhtml#sctp-parameters-24 If the m= line is rejected or removed from SDP, an error will again be sent to the data channels, signaling their unexpected transition to closed. Bug: webrtc:12904 Change-Id: Iea3d8aba0a57bbedb5d03f0fb6f7aba292e92fe8 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/223541 Reviewed-by: Harald Alvestrand <hta@webrtc.org> Commit-Queue: Harald Alvestrand <hta@webrtc.org> Commit-Queue: Florent Castelli <orphis@webrtc.org> Cr-Commit-Position: refs/heads/master@{#34386}