Re: [rtcweb] JSEP: Relaxing SDP O/A rules?

Christer Holmberg <> Fri, 05 October 2012 21:31 UTC

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From: Christer Holmberg <>
To: Martin Thomson <>
Date: Fri, 5 Oct 2012 23:26:59 +0200
Thread-Topic: [rtcweb] JSEP: Relaxing SDP O/A rules?
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Subject: Re: [rtcweb] JSEP: Relaxing SDP O/A rules?
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>>>> If you want to support parallel forking, you need to be able to simultanously perform ICE etc with all remote peers.
>>> Right.  You can almost get that by pretending that it's just one
>>> remote peer with lots of candidates.  You can at least get to the
>>> consent point by doing that.  But you aren't going to nominate more
>>> than one pair.  Similarly, this will only generate a single DTLS
>>> session.
>> I was thinking about the same once, but I think I found some issues (unfortunately they don't come to my mind at the moment).
> It's probably not going to be flawless, true.  As you say, media would
> be a little crazy.  You might be able to get one media stream out of
> it - not multiple.

And, I guess it would still require to be able to update the answer, as additional early dialogs (with associated remote ICE candidates) may be created.

>> Can I use the same local descriptor for every setLocal() call?
> My experience suggests that you can.  However, that's not stipulated
> in the API specification, so it's not an ironclad guarantee.

If it doesn't, and a new local descripor is created, you would need to send that one to the remote endpoint.