Re: [webrtc-pc] Nulling mid when m-line is recycled is surprising. (#2238)

My intuition says that clearing the mid property was designed to maintain the property that "all transceivers have a mid that is either unique or null".

In particular, the offer/answer exchange:

-> offer: m=video port=5 / a=mid=a

creates a transceiver with mid=a

<- answer: m=video port=0

disassociates the transceiver from the m-line.
If a new offer comes in:

<- offer: m=video port=97 / a=mid=a

will create a new transceiver with mid=a

If we don't clear, we now have two transceivers with mid=a, one of them stopped.

My point of confusion may be the statement "the mid can't be reused anyway", which I can't remember offhand that we have an explicit agreement to (and since mid can come in from non-webrtc endpoints, that agreement needs to be in the sdp spec, not in webrtc spec).



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Received on Thursday, 1 August 2019 13:22:06 UTC