Hi, >The majority of the specification talks about a UA as client and an edge proxy >as server. The only hint that it might be >applied in other situations is in section 8 "Overlap with connection reuse", >but there is no normative language there. So >the scope clearly seems to be between a UA and an edge proxy, and I don't see >much value in that (i.e., might as well >support sip-outbound).
Outbound can not always be used, as the draft says. It is true that initially the primary scope is between the UA and the edge proxy. However, I am happy to add the proxy-to-proxy use-case, if people think that is something we should do. >If you wish to extend the scope so that it can operate between any two SIP >entities, and in particular between two >proxies, then that is a different matter. There may be valid use cases, but I >can't recall whether these have been >discussed. Will the same technical solution apply (e.g., in terms of which >side is the client, which side chooses the >timer value, what is the default timer value, etc.)? At the moment I see no reason why the same technical solution wouldn't apply. Regards, Christer I think Keith's questions related to the present draft (01) and I interpret the scope as UA to edge proxy only. If you wish to extend the scope, this would require a revised draft before making any decision on adopting as a work item. John > -----Original Message----- > From: Christer Holmberg [mailto:[EMAIL PROTECTED] > Sent: 24 June 2008 08:20 > To: Elwell, John; Hadriel Kaplan; DRAGE, Keith (Keith); [email protected] > Subject: RE: [Sip] Progress draft-holmberg-sip-keep > > > Hi John, > > SIP-keep CAN be used proxy-to-proxy, B2BUA-to-B2BUA etc. ANY entity > (e.g. a proxy) can insert the keep parameter in its Via header, and if > the next entity adds a "yes" value the "keep-alives" can be used > between those entities. > > Regards, > > Christer > > > -----Original Message----- > From: Elwell, John [mailto:[EMAIL PROTECTED] > Sent: 24. kesäkuuta 2008 10:15 > To: Hadriel Kaplan; DRAGE, Keith (Keith); [email protected] > Cc: Christer Holmberg > Subject: RE: [Sip] Progress draft-holmberg-sip-keep > > Hadriel, > > Concerning your "PBX connections a la SIP trunks" use case, I am not > convinced of this. ETSI TISPAN has specified two ways for an IPPBX to > connect to a service provider. One is the so-called subscription-based > approach, where the IPPBX registers with the SP and communicates via > an edge proxy. In this case, why not use SIP-outbound? The other is > the so-called peering-based approach, which is essentially the same as > any SIP "trunk", e.g., proxy-to-proxy, B2BUA-to-B2BUA, > proxy-to-gateway. > SIP-outbound does not apply to these situations, and similarly the > keep-alive mechanism is not specified for this cases. The requirements > in SIP-keep do not cover these situations. > > Basically I am not sold on the idea of a separate SIP-keep spec - I > don't think it would be the best use of WG time. > > John > > > > -----Original Message----- > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of > > Hadriel Kaplan > > Sent: 20 June 2008 18:20 > > To: DRAGE, Keith (Keith); [email protected] > > Cc: Christer Holmberg > > Subject: Re: [Sip] Progress draft-holmberg-sip-keep > > > > > > My 2 cents: it is a useful draft. Personally, I would like > to have it > > available for two reasons not cited: PBX connections a la > SIP trunks, > > and proxy-proxy connections. > > Today I think a lot of people are using OPTIONS requests or > > proprietary means to perform such keep-alives when > registration is not > > appropriate, but it has led to some interop issues and performance > > concerns in some cases. > > > > Since the contentious issue of what form the keep-alives take have > > already been agreed on for outbound, this seems like a > simple draft to > > get done. (famous last words, I know) > > > > -hadriel > > > > > > > -----Original Message----- > > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > > Behalf Of > > > DRAGE, Keith (Keith) > > > Sent: Thursday, June 19, 2008 5:31 AM > > > To: [email protected] > > > Cc: Christer Holmberg > > > Subject: [Sip] Progress draft-holmberg-sip-keep > > > > > > (As SIP WG cochair) > > > > > > We have been asked by the author of > > > > > > http://www.ietf.org/internet-drafts/draft-holmberg-sip-keep-01.txt > > > > > > Whether the SIP WG can progress this document. > > > > > > Because this draft arose as a result of the discussion of > > outbound, and > > > indeed seems to reuse the requirements from outbound, and these > > > requirements never really got handled in the SIPPING WG, > it has been > > > agreed with the SIPPING chairs that we will handle this > > entirely within > > > SIP. > > > > > > Now in order to ask for charter milestones, and indeed when > > we finally > > > present this to IESG, we will be asked for the level of > > support in the > > > WG, which is also predicated on does this fix a real > > problem, or is it > > > just a corner case with limited application. So: > > > > > > QUESTION 1 TO SIP WG: Are the use cases sufficiently important to > > > proceed with this draft? The document states: > > > > > > Chapter 3.5 of draft-ietf-sip-outbound-13 > [I-D.ietf-sip-outbound] > > > defines two keep-alive techniques. Even though the keep-alive > > > techniques are separated from the Outbound mechanism > > > [I-D.ietf-sip-outbound], it is currently not possible > to indicate > > > support of the keep-alive techniques without also > > indicating support > > > for the Outbound mechanism. > > > > > > The Outbound mechanism is enabled during the UA > > registration phase. > > > However, there are use-cases where the UA does not > > register itself, > > > but still needs to be able to make calls and maintain > > NAT bindings > > > open during the duration of that call. A typical example is > > > emergency calls. There are also cases where entities do > > not support > > > the Outbound mechanism, but still want to be able to > > indicate support > > > and use the keep-alive techniques defined in > > [I-D.ietf-sip-outbound]. > > > > > > At first sight this is not the most inspiring declaration > > of the need > > > for the document. Please respond indicating whether you > > consider this a > > > useful draft, and propose text that you think would be > > useful in this > > > section. Conversely, if you think this draft is not useful > > and the WG > > > has other more important things to work on first, please > > also respond. > > > > > > QUESTION 2 TO SIP WG: Do we have a robust set of requirements for > > > proceeding with this work? The document currently lists: > > > > > > REQ 1: It MUST be possible for a UA to indicate support > > of the keep- > > > alive techniques defined [I-D.ietf-sip-outbound] if the > > UA supports > > > only the keep-alive part of [I-D.ietf-sip-outbound]. > > > > > > REQ 2: It MUST be possible for an edge proxy to indicate > > support of > > > the keep-alive techniques defined > > [I-D.ietf-sip-outbound] if the edge > > > poxy supports only the keep-alive part of > > [I-D.ietf-sip-outbound]. > > > > > > It would be desirable to agree these at the outset, and not > > revisit them > > > if we continue with the work. So if you require clarification, > > > modification, or addition to these two requirements, then > > please also > > > response with your questions and proposals. > > > > > > I suggest we would like responses by 30th June 2008 in > > order to allow > > > the author to revise the document before the deadlines. > > Please note that > > > we are looking to make this decision on the list within > > this deadline > > > based on responses received, not leave it until the > Dublin meeting. > > > > > > Regards > > > > > > Keith > > > _______________________________________________ > > > Sip mailing list https://www.ietf.org/mailman/listinfo/sip > > > This list is for NEW development of the core SIP Protocol Use > > > [EMAIL PROTECTED] for questions on current sip Use > > > [EMAIL PROTECTED] for new developments on the application of sip > > _______________________________________________ > > Sip mailing list https://www.ietf.org/mailman/listinfo/sip > > This list is for NEW development of the core SIP Protocol Use > > [EMAIL PROTECTED] for questions on current sip Use > > [EMAIL PROTECTED] for new developments on the application of sip > > > _______________________________________________ Sip mailing list https://www.ietf.org/mailman/listinfo/sip This list is for NEW development of the core SIP Protocol Use [EMAIL PROTECTED] for questions on current sip Use [EMAIL PROTECTED] for new developments on the application of sip
