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RE: Microsoft API Proposal

From: Jim Barnett <Jim.Barnett@genesyslab.com>
Date: Thu, 9 Aug 2012 08:50:02 -0700
Message-ID: <E17CAD772E76C742B645BD4DC602CD81068E13B7@NAHALD.us.int.genesyslab.com>
To: "Martin Thomson" <martin.thomson@gmail.com>
Cc: "Stefan Hakansson LK" <stefan.lk.hakansson@ericsson.com>, <public-webrtc@w3.org>
Martin,
  Yes, it's true that the building the signaling channel is the application's problem.  I'm wondering about how the applications interpret the messages that are sent on the signaling channel.  SDP specifies a syntax and semantics, so that when an application receives an SDP message over the signaling channel, it knows what it is and how to interpret it.  How will an application know that the message it has received over the signaling channel is a RealTimeMedia description?  

- Jim

-----Original Message-----
From: Martin Thomson [mailto:martin.thomson@gmail.com] 
Sent: Thursday, August 09, 2012 11:44 AM
To: Jim Barnett
Cc: Stefan Hakansson LK; public-webrtc@w3.org
Subject: Re: Microsoft API Proposal

On 7 August 2012 10:37, Jim Barnett <Jim.Barnett@genesyslab.com> wrote:
> On the issue of replacing SDP, I'm trying to understand how the RealTimeMedia description would be signaled between the peers.  Examples 1 and 2 in Section 2 show side A calling:
>   signalingChannel.send(description.toDictionary());
>
> Then on the receiving side B we have:
>  function receiveDescriptionFromSignaling(remoteDescription) {.....
>
> So it appears that something on side B had to receive the message, recognize that it was a RealTimeMediaDictionary, build the appropriate structure, and then call receiveDescriptionFromSignalling.  Is the browser supposed to do this?  How would the two ends agree on the signaling protocol?  I thought that the point of SDP was to solve this kind of problem.  You may have a better solution in mind, but I haven't been able to figure out what it is.

Sorry for missing this in the flood.  SDP does not solve the problem of how the signaling channel is built.  That is always the application's problem.  JSEP still requires all these actions to occur in much the same way.  In this regard, both specifications are essentially identical.
Received on Thursday, 9 August 2012 15:51:21 GMT

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