Re: [webrtc-pc] Clarify a=ssrc attributes when track is changed/removed (#2783)

I reproduced this in Brave too(seems to be a Chromium specific issue). Here's a diff of the SDPs:


```diff
Diff from server-send-2 to server-send-4(track removed offer)
 a=rtcp-fb:96 nack
 a=rtcp-fb:96 nack pli
 a=extmap:3 urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id
 a=extmap:4 http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01
-a=ssrc:2785765189 cname:Yz65FqPRNNmJNgdhffEa.camera
-a=ssrc:2785765189 msid:Yz65FqPRNNmJNgdhffEa.camera tmNYQyngD6qxeHFDD.cam
-a=ssrc:2785765189 mslabel:Yz65FqPRNNmJNgdhffEa.camera
-a=ssrc:2785765189 label:tmNYQyngD6qxeHFDD.cam
 a=msid:Yz65FqPRNNmJNgdhffEa.camera tmNYQyngD6qxeHFDD.cam
-a=sendonly
+a=inactive


Diff from browser-send-3 to browser-send-5(browser answer)
 a=extmap:2 urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id
 a=extmap:3 urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id
-a=recvonly
+a=inactive

Diff from server-send-4 to server-send-6(track re-added offer)
 a=extmap:1 urn:ietf:params:rtp-hdrext:sdes:mid
 a=extmap:2 urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id
+a=ssrc:2785765189 cname:Yz65FqPRNNmJNgdhffEa.camera
+a=ssrc:2785765189 msid:Yz65FqPRNNmJNgdhffEa.camera tmNYQyngD6qxeHFDD.cam
+a=ssrc:2785765189 mslabel:Yz65FqPRNNmJNgdhffEa.camera
+a=ssrc:2785765189 label:tmNYQyngD6qxeHFDD.cam
 a=msid:Yz65FqPRNNmJNgdhffEa.camera tmNYQyngD6qxeHFDD.cam
-a=inactive
+a=sendonly


Diff from browser-send-5 to browser-send-7(browser answer)
 a=extmap:2 urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id
 a=extmap:3 urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id
-a=inactive
+a=recvonly




```

-- 
GitHub Notification of comment by k0nserv
Please view or discuss this issue at https://github.com/w3c/webrtc-pc/issues/2783#issuecomment-1297353020 using your GitHub account


-- 
Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config