Figure out exactly when onnegotiationneeded is fired

rtcweb-wg / jsep

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Figure out exactly when onnegotiationneeded is fired #26

Closed juberti closed 9 years ago

juberti commented 10 years ago

Right now, any changes to the session, via addStream/addTrack, or tweaks on the upcoming RtpSender object, trigger onnegotiationneeded. This makes handling of onnegotiationneeded by the application difficult.

Harald suggests only firing onnegotiationneeded when in the stable state. This doesn't solve the situation fully when you add multiple tracks, but it should allow applications to always call createOffer in response to an onnegotiationneeded.

Cullen also is concerned about how Harald's proposal would interact with PRANSWER.

martinthomson commented 10 years ago

Note that you would have to fire the event when you enter stable state if there are outstanding changes that weren't captured properly by the last round of negotiation. For example, if you have more tracks than you could add to m= sections in an answer.

juberti commented 10 years ago

Discussion at IETF 90 established this baseline:

onnegotiationneeded only fires in JS stable state (it has to)
onnegotiationneeded only fires in JSEP stable state (should also rename JSEP stable state to avoid confusion)
(need to check) onnegotiationneeded works like a dirty bit - once fired, it doesn't fire again until the desired negotiation is completed
any changes to the session while not in stable state get queued until JSEP returns back to the stable state
onnegotiationneeded fires on the initial AddTrack (unless problematic case found)

juberti commented 10 years ago

Also, need to understand what should happen while in PRANSWER state - should changes send new PRANSWER? I think probably not, since not all changes can be communicated in PRANSWER (e.g. new track that requires new m- line)

juberti commented 10 years ago

Resolving PRANSWER to be done by Thursday PM

ekr commented 10 years ago

removing discuss tag since this is on justin

juberti commented 10 years ago

Resolution was to never send onnegotiationneeded in any state other than stable. Basically, onNN just means "you need to do the offer/answer dance".

juberti commented 9 years ago

Closing as out of scope for JSEP. Currently being handled in https://github.com/w3c/webrtc-pc/pull/186