Re: [rtcweb] Minimal SDP negotiation mechanism
Harald Alvestrand <harald@alvestrand.no> Wed, 21 September 2011 09:48 UTC
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Date: Wed, 21 Sep 2011 11:51:25 +0200
From: Harald Alvestrand <harald@alvestrand.no>
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Cc: "rtcweb@ietf.org" <rtcweb@ietf.org>
Subject: Re: [rtcweb] Minimal SDP negotiation mechanism
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On 09/20/2011 03:24 PM, Magnus Westerlund wrote: > On 2011-09-19 18:59, Harald Alvestrand wrote: > >> We need to handle glare - when one sends an OFFER and gets back an >> OFFER, reply with SDP ERROR, enter a "glare" state, wait a bit, and send >> out an offer again. >> > I think that is a bad design for glare handling. I agree it needs to be > handled. I think the ICE version of glare handling could work pretty > well here. Any offer needs to include a random 32 bit number. If the > end-point receive an offer in relation to a peer-connection while it has > an outstanding offer then it compares these codes. Who ever has the > greatest numerical value wins and that offer is handled the other is > responded with an error stating GLARE. Thus there is no extra delay and > more clear resolution of the glare case. Hm... thinking about it, I think this can be incorporated. The reason it works is that the signalling channel is supposed to guarantee reliable, ordered delivery, so we know that both parties agree that a glare condition exists. (actually, that condition doesn't hold for ICE, so I'm a bit surprised it works there.) If we specify that the random number is 1 < N < MAXINT, we can even incorporate the SIP interworking case by saying that a gateway can force the party into GLARE by specifying one of the edge cases - whatever makes interworking happy.
- Re: [rtcweb] Minimal SDP negotiation mechanism Olle E. Johansson
- [rtcweb] Minimal SDP negotiation mechanism Harald Alvestrand
- Re: [rtcweb] Minimal SDP negotiation mechanism Paul Kyzivat
- Re: [rtcweb] Minimal SDP negotiation mechanism Hadriel Kaplan
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Olle E. Johansson
- Re: [rtcweb] Minimal SDP negotiation mechanism Christer Holmberg
- Re: [rtcweb] Minimal SDP negotiation mechanism Iñaki Baz Castillo
- Re: [rtcweb] Minimal SDP negotiation mechanism Harald Alvestrand
- Re: [rtcweb] Minimal SDP negotiation mechanism Christer Holmberg
- Re: [rtcweb] Minimal SDP negotiation mechanism Christer Holmberg
- Re: [rtcweb] Minimal SDP negotiation mechanism Harald Alvestrand
- Re: [rtcweb] Minimal SDP negotiation mechanism Olle E. Johansson
- Re: [rtcweb] Minimal SDP negotiation mechanism Christer Holmberg
- Re: [rtcweb] Minimal SDP negotiation mechanism Iñaki Baz Castillo
- Re: [rtcweb] Minimal SDP negotiation mechanism Magnus Westerlund
- Re: [rtcweb] Minimal SDP negotiation mechanism Roman Shpount
- Re: [rtcweb] Minimal SDP negotiation mechanism Olle E. Johansson
- Re: [rtcweb] Minimal SDP negotiation mechanism Cullen Jennings
- [rtcweb] Forking & Early Media - Was Re: Minimal … Cullen Jennings
- Re: [rtcweb] Minimal SDP negotiation mechanism Cullen Jennings
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Cullen Jennings
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Olle E. Johansson
- Re: [rtcweb] Minimal SDP negotiation mechanism Hadriel Kaplan
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Dzonatas Sol
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Hadriel Kaplan
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Hadriel Kaplan
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Ravindran Parthasarathi
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Roman Shpount
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Olle E. Johansson
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Ravindran Parthasarathi
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Saúl Ibarra Corretgé
- Re: [rtcweb] Minimal SDP negotiation mechanism Harald Alvestrand
- Re: [rtcweb] Forking & Early Media - Proposal Randell Jesup
- Re: [rtcweb] Forking & Early Media - Proposal Olle E. Johansson
- Re: [rtcweb] Minimal SDP negotiation mechanism Magnus Westerlund
- Re: [rtcweb] Minimal SDP negotiation mechanism Harald Alvestrand
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Muthu Arul Mozhi Perumal (mperumal)
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Roman Shpount
- Re: [rtcweb] Forking & Early Media - Proposal Roman Shpount
- Re: [rtcweb] Forking & Early Media - Proposal Randell Jesup
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Hadriel Kaplan
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Cullen Jennings
- [rtcweb] SIP Glare - Re: Minimal SDP negotiation … Cullen Jennings
- Re: [rtcweb] SIP Glare - Re: Minimal SDP negotiat… Tim Panton
- Re: [rtcweb] SIP Glare - Re: Minimal SDP negotiat… Hadriel Kaplan
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Roman Shpount
- Re: [rtcweb] SIP Glare - Re: Minimal SDP negotiat… Roman Shpount
- Re: [rtcweb] SIP Glare - Re: Minimal SDP negotiat… Magnus Westerlund
- Re: [rtcweb] Forking & Early Media - Proposal Elwell, John
- Re: [rtcweb] SIP Glare - Re: Minimal SDP negotiat… Harald Alvestrand
- Re: [rtcweb] SIP Glare - Re: Minimal SDP negotiat… Iñaki Baz Castillo
- Re: [rtcweb] SIP Glare - Re: Minimal SDP negotiat… Cullen Jennings
- Re: [rtcweb] SIP Glare - Re: Minimal SDP negotiat… Dzonatas Sol
- Re: [rtcweb] SIP Glare - Re: Minimal SDP negotiat… Matthew Kaufman
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Christer Holmberg
- Re: [rtcweb] SIP Glare - Re: Minimal SDP negotiat… Iñaki Baz Castillo
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Christer Holmberg
- Re: [rtcweb] SIP Glare - Re: Minimal SDP negotiat… Cullen Jennings
- Re: [rtcweb] SIP Glare - Re: Minimal SDP negotiat… Iñaki Baz Castillo
- Re: [rtcweb] SIP Glare - Re: Minimal SDP negotiat… Cullen Jennings
- Re: [rtcweb] SIP Glare - Re: Minimal SDP negotiat… Matthew Kaufman
- Re: [rtcweb] SIP Glare - Re: Minimal SDP negotiat… Christer Holmberg
- Re: [rtcweb] SIP Glare - Re: Minimal SDP negotiat… Cullen Jennings
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Hadriel Kaplan
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Roman Shpount
- Re: [rtcweb] SIP Glare - Re: Minimal SDP negotiat… Randell Jesup
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Christer Holmberg
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Christer Holmberg
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Hadriel Kaplan
- Re: [rtcweb] SIP Glare - Re: Minimal SDP negotiat… Magnus Westerlund
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Harald Alvestrand
- Re: [rtcweb] Forking & Early Media - Was Re: Mini… Christer Holmberg