Re: [rtcweb] Why SDP answer needs and ack … was Re: SDP Offer/Answer draft-jennings-rtcweb-signaling
Iñaki Baz Castillo <ibc@aliax.net> Tue, 18 October 2011 19:44 UTC
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Date: Tue, 18 Oct 2011 21:44:06 +0200
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From: Iñaki Baz Castillo <ibc@aliax.net>
To: Cullen Jennings <fluffy@cisco.com>
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Cc: Jonathan Rosenberg <jonathan.rosenberg@skype.net>, rtcweb@ietf.org, public-webrtc@w3.org
Subject: Re: [rtcweb] Why SDP answer needs and ack … was Re: SDP Offer/Answer draft-jennings-rtcweb-signaling
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2011/10/18 Cullen Jennings <fluffy@cisco.com>: > Hi - glad to hear you see this going the right direction. On the topic of why we have an OK, let me provide a bit of the motivation. > > When one side sends and answer that says it wants to receive VP8 instead of H.264, it's probably useful to know when the other side got that information. This might impact the timing of when o send things or user interface that provides feedback about the status of the other side. We are also dealing with a web transaction model where transaction are not guarantee to happen even if they are sent over TCP. So you need to get back a response to request. It also helps with mapping to SIP but even if you were not mapping to another protocol, I suspect you would still need to be able to have an confirmation than and answer was received. Hi Cullen. Let me put an example: - alice: JS client implementing pure SIP over WebSocket. - A proxy implementing SIP over UDP and WebSocket. - bob: SIP UDP client. The flows: - alice sends INVITE to bob with an empty body (no SDP). - bob replies a 200 with the SDP offer. - alice receives the 200. Its JS code internally generates a ROAP Offer. - alice generates a ROAP Answer and inserts its SDP into an ACK to be sent to bob. - In SIP we have ended. So how is supposed alice will receive the ROAP OK message? I don't understand yet if such ROAP OK message is mandatory to be sent to the RTCweb stack. If so, the JS code in alice could auto-generate it after sending the ACK, so the RTCweb stack becomes happy. But obviously the advantage of such auto-generated ROAP OK is null. Regards. -- Iñaki Baz Castillo <ibc@aliax.net>
- [rtcweb] SDP Offer/Answer draft-jennings-rtcweb-s… Cullen Jennings
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Iñaki Baz Castillo
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Iñaki Baz Castillo
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Ravindran Parthasarathi
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Iñaki Baz Castillo
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Ravindran Parthasarathi
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Iñaki Baz Castillo
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Ted Hardie
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Roman Shpount
- [rtcweb] API options for supporting fork with ROA… Harald Alvestrand
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Christer Holmberg
- Re: [rtcweb] API options for supporting fork with… Iñaki Baz Castillo
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Iñaki Baz Castillo
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Christer Holmberg
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Iñaki Baz Castillo
- Re: [rtcweb] API options for supporting fork with… Harald Alvestrand
- Re: [rtcweb] API options for supporting fork with… Iñaki Baz Castillo
- Re: [rtcweb] API options for supporting fork with… Stefan Håkansson LK
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Roy, Radhika R USA CIV (US)
- Re: [rtcweb] API options for supporting fork with… Iñaki Baz Castillo
- Re: [rtcweb] API options for supporting fork with… Stefan Håkansson LK
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Magnus Westerlund
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Iñaki Baz Castillo
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Eric Rescorla
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… BeckW
- Re: [rtcweb] API options for supporting fork with… Roman Shpount
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Eric Rescorla
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Cullen Jennings
- [rtcweb] Why SDP answer needs and ack … was Re: S… Cullen Jennings
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Cullen Jennings
- [rtcweb] Forking -Re: SDP Offer/Answer draft-jenn… Cullen Jennings
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Cullen Jennings
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Iñaki Baz Castillo
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Ravindran Parthasarathi
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Cullen Jennings
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Cullen Jennings
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Harald Alvestrand
- Re: [rtcweb] Why SDP answer needs and ack … was R… Iñaki Baz Castillo
- Re: [rtcweb] Why SDP answer needs and ack … was R… Harald Alvestrand
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Stefan Håkansson
- Re: [rtcweb] API options for supporting fork with… Stefan Håkansson
- Re: [rtcweb] API options for supporting fork with… Harald Alvestrand
- [rtcweb] Draft name change: draft-holmberg-mmusic… Christer Holmberg
- Re: [rtcweb] API options for supporting fork with… Stefan Håkansson LK
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Christer Holmberg
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Christer Holmberg
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Christer Holmberg
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Christer Holmberg
- Re: [rtcweb] Forking - Re: SDP Offer/Answer draft… Christer Holmberg
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Cullen Jennings
- Re: [rtcweb] Forking - Re: SDP Offer/Answer draft… Cullen Jennings
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Cullen Jennings
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Cullen Jennings
- Re: [rtcweb] Why SDP answer needs and ack … was R… Cullen Jennings
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Marc Petit-Huguenin
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Cullen Jennings
- Re: [rtcweb] Why SDP answer needs and ack … was R… Randell Jesup
- Re: [rtcweb] Why SDP answer needs and ack … was R… Hadriel Kaplan
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Christer Holmberg
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Christer Holmberg
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Christer Holmberg
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Cullen Jennings
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Harald Alvestrand
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Christer Holmberg
- Re: [rtcweb] SDP Offer/Answer draft-jennings-rtcw… Cullen Jennings