- From: Harald Alvestrand <harald@alvestrand.no>
- Date: Mon, 25 Apr 2016 10:07:59 +0200
- To: Eric Rescorla <ekr@rtfm.com>
- Cc: "public-webrtc@w3.org" <public-webrtc@w3.org>
Den 18. april 2016 01:12, skrev Eric Rescorla: > > > On Wed, Apr 13, 2016 at 7:12 AM, Harald Alvestrand <harald@alvestrand.no > <mailto:harald@alvestrand.no>> wrote: > > On 04/13/2016 01:26 AM, Taylor Brandstetter wrote: >> My initial assumption was that the only purpose of the >> "max-bundle" policy was to create "bundle-only" media descriptions >> in an offer. >> >> But a question came up recently: What happens if you receive a >> non-BUNDLE offer when the max-bundle policy is configured? >> >> Should the PeerConnection: >> >> 1. Allow this, and negotiate multiple transports? >> 2. Reject (port 0) all but one of the media descriptions? >> >> An application developer may be surprised if they configure >> max-bundle, but end up non-bundled. But conversely, they may be >> surprised if media descriptions are rejected for no reason other >> than the bundle policy. >> > My immediate reaction (on the general principle that "negotation to > less functionality should always work") is that the developer's > setting for max-bundle policy affects offers created by the local PC > only; if the implementation is at all able to accept the remote > side's offer, it should accept it. > > I think we still require all implementations to support multiple > transports. > > > I think we should reject this for the same reason that we reject non-mux > offers when mux=require. It avoids situations where two endpoints can > initially communicate but then cannot if a subsequent negotiation > happens in the other direction. Can you give an example of a negotiation where this would happen? If we accept the premise that renegotiation can't change the "bundle-only" property of existing m-lines, I don't see how we can get into trouble. That is: (A doesn't bundle, B has policy max-bundle) A: Offer X, Y B: Answer X, Y (no bundle) Policy alternative 1, B tries to bundle what it can: B: Offer X, Y, Z, W; Z and W are bundled, W is marked bundle-only A: Answer X, Y, Z; rejects W, since it was marked bundle-only Communication continues on X, Y and Z Policy alternative 2, B understands that bundle-only won't succeed B: Offer, X, Y, Z, W - doesn't bundle, or bundles Z and W with no bundle-only A: Answer X, Y, Z, W - no bundle Communication continues on X, Y, Z, W I don't see the failure scenario that rejecting the initial offer would help us avoid.
Received on Monday, 25 April 2016 08:08:32 UTC