Re: [rtcweb] Summary of Application Developers' opinions of the current WebRTC API and SDP as a control surface

Iñaki Baz Castillo <> Mon, 08 July 2013 20:43 UTC

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From: Iñaki Baz Castillo <>
Date: Mon, 08 Jul 2013 22:43:26 +0200
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To: Stefan Håkansson LK <>
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Subject: Re: [rtcweb] Summary of Application Developers' opinions of the current WebRTC API and SDP as a control surface
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2013/7/8 Stefan Håkansson LK <>:
>> So, was there ever a consensus that "developers MUST NOT
>> touch SDP"?
> No, developers are free to touch the SDP (and probably must in certain
> cases).

Do you feel how much painful is "touching a browser generated SDP"? To be clear:

- JS requests "A" to browser.
- Browser returns "A" (in the form of unmanageable blob).
- JS modifies "A" to send "A-bis" in the wire.
- Remote peer receives "A-bis" and replies "B-bis".
- Both JS app are lying to their respective  browsers to get the
desired behavior.

This is really painful, really.

In the other side, as I explained in other thread (may be in this
one?) adding some methods to the current API (to avoid playing with
the SDP) is not the way to go. A specification in which the JS app
does not know what he is sending in-the-wire (a blob generated by the
browser) is doomed to failure.

Please remember that mandating SDP (plain SDP) means that no other
media signaling protocol can be implemented in future WebRTC apps.

SIP phones have *fixed* code and *fixed* logic. This is no longer true
in the Web.

Iñaki Baz Castillo