RE: draft-ietf-mmusic-sip-session-timer-00.txt
Pat.Calhoun@Eng.Sun.COM (Patrice Calhoun) Fri, 12 February 1999 01:25 UTC
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From: Pat.Calhoun@Eng.Sun.COM
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Date: Thu, 11 Feb 1999 17:20:55 -0800
To: Francois Menard Distribution List Management Account <fm-listproc@mediatrix.com>, "'iptel@lists.research.bell-labs.com'" <iptel@lists.research.bell-labs.com>, "'confctrl@ISI.EDU'" <confctrl@ISI.EDU>, "Donovan, Steven R. (MCI)" <Steven.R.Donovan@mci.com>, "'Pat.Calhoun@Eng.Sun.COM'" <Pat.Calhoun@Eng.Sun.COM>
Reply-To: Pat.Calhoun@Eng.Sun.COM
Subject: RE: draft-ietf-mmusic-sip-session-timer-00.txt
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>There is no way to properyly time the session unless the end-point is a >controlled network element. A gatekeeper and/or SIP server cant do anything >unless the media stream gets through it ... of course, a SIP server, and or >H.323 gatekeeper can talk to routers, which control an IP media stream, and >affect the media stream. > >Even worse, a sip server / gatekeeper that wishes to track the end of a call >so that it can bill by the second needs to worry about end points that just >go out and die and never send an end of conversation ... this mechanism is >not yet specified ... Yes the cellular network that the same problem, hence the "end" button on your phone. This would require a periodical update from the SIP Client to the SIP Server (a refresh of some sort). PatC > >-=Francois=- > >-----Original Message----- >From: Pat.Calhoun@Eng.Sun.COM [mailto:Pat.Calhoun@Eng.Sun.COM] >Sent: Thursday, February 11, 1999 6:22 PM >To: Donovan, Steven R. (MCI); 'confctrl@ISI.EDU'; >'iptel@lists.research.bell-labs.com'; 'Pat.Calhoun@Eng.Sun.COM' >Subject: RE: draft-ietf-mmusic-sip-session-timer-00.txt > > > >> >> >>> -----Original Message----- >>> From: Pat.Calhoun@Eng.Sun.COM [SMTP:Pat.Calhoun@Eng.Sun.COM] >>> Sent: Thursday, February 11, 1999 1:02 PM >>> To: Donovan, Steven R. (MCI); 'iptel@lists.research.bell-labs.com'; >>> 'confctrl@ISI.EDU' >>> Subject: RE: draft-ietf-mmusic-sip-session-timer-00.txt >>> >>> Pardon the perhaps very naive question, but I suppose I am not as versant >>> in >>> SIP as I would like to be. >>> >>> My understanding is that a SIP Client issues an Invite message to a SIP >>> Server, >>> which in turn forwards the request to a target SIP Client (or some GW or >>> some >>> sort). Once the ACK has returned to the originating client, I was under >>> the >>> impression that both SIP Clients send RTP packets directly to each other, >>> bypassing the SIP Server (this is where I am unclear). >>> >> This depends on the implementation of the SIP Server. There are >>valid reasons to have the SIP Server proxy the IP packets. But in general, >>you are correct. There will be SIP Servers that do not have a view of the >>RTP flow. >> >>> So if this is true, how will a SIP Server (stateful, or stateless) >enforce >>> any >>> session timeouts? A malicious SIP Client can simply keep the session >>> active >>> for as long as it wishes, ignoring any messages from the SIP Server that >>> may >>> tell it to disconnect. >>> >>> This, as far as I can see, could cause some serious problems if one >wishes >>> to >>> deploy a service and still maintain some control over the sessions. >>> >>> Again, perhaps I am way off here. Any clarifications would certainly be >>> appreciated. >>> >> You are correct and I personally would not rely on reporting from >>the SIP Server to do reliable billing. However, if a stateful SIP Proxy >>server is built, for whatever reason, the current SIP specification does >not >>have a mechanism for the SIP server to know which of the sessions for which >>it has state are valid. This draft gives the SIP Server a mechanism to >>remove those sessions that it feels are no longer valid. >> >> The amount of control that a SIP server exerts over sessions is a >>separate issue. As John Hearty accurately points out in a separate email, >>the user of the SIP device can choose to bypass the SIP server entirely. >>The challenge for service providers will be to implement services that make >>user's want to access the service provider's SIP server. > >This is not actually true. It is quite simple for service providers to >install >a set of filters in their systems that require that all RTP traffic be >directed >to one of their local SIP Servers. > >Note that I am not advocating such an idea. I like free service, but one >must >realize that free services are rarely every deployed by the services >providers :( > >PatC >> >>> PatC >>> >>> >This time with the draft attached. Sorry for the extra mail. >>> > >>> >Steve >>> > >>> > <<draft-ietf-mmusic-sip-session-timer-00.txt>> >>> > >>> >> -----Original Message----- >>> >> From: Donovan, Steven R. (MCI) >>> >> Sent: Thursday, February 11, 1999 10:17 AM >>> >> To: 'confctrl@ISI.EDU'; 'iptel@lists.research.bell-labs.com' >>> >> Subject: draft-ietf-mmusic-sip-session-timer-00.txt >>> >> >>> >> This message is notification of the following Internet Draft which has >>> >> been submitted to the IETF for posting. >>> >> >>> >> <draft-ietf-mmusic-sip-session-timer-00.txt> >>> >> >>> >> Abstract: >>> >> >>> >> This document proposes an extension to the SIP specification. This >>> >> extension adds a new message header that is used to specify the >>> >> duration of a requested session. >>> >> >>> >> The session timer can be used to limit the total duration of a session >>> >> if, for instance, one of the participants in the session wants to >>> >> limit the cost of the session. It can also be used by stateful SIP >>> >> Proxy Servers to track the status of sessions for which session state >>> >> exists on the servers. Currently a stateful SIP Proxy Server that is >>> >> not handling the media stream(s) for the session has no mechanism to >>> >> definitively determine the state of all sessions for which it has >>> state. >>> >> While the SIP Specification does provide the BYE method for >terminating >>> >> the session, there is no mechanism for a SIP Proxy Server to detect >the >>> >> end of a session when the BYE message is not sent or is lost due to >>> >> network problems. >>> >> >>> >> The internet draft is attached. >>> >> >>> >> Steve Donovan >>> >> MCIWorldcom >>> > > > >--------- >This message came from the IETF IPTEL Working Group Mailing List.
- draft-ietf-mmusic-sip-session-timer-00.txt Donovan, Steven R. (MCI)
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Donovan, Steven R. (MCI)
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Patrice Calhoun
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Jonathan Rosenberg
- RE: draft-ietf-mmusic-sip-session-timer-00.txt John Hearty
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Donovan, Steven R. (MCI)
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Patrice Calhoun
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Douglas Clowes
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Patrice Calhoun
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Francois Menard Distribution List Management Account
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Patrice Calhoun
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Douglas Clowes
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Douglas Clowes
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Jonathan Rosenberg
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Henning Schulzrinne
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Francois Menard Distribution List Management Account
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Jonathan Rosenberg
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Vipin Palawat
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Patrice Calhoun
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Patrice Calhoun
- RE: RE: draft-ietf-mmusic-sip-session-timer-00.txt Francois Menard
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Jonathan Rosenberg
- RE: RE: draft-ietf-mmusic-sip-session-timer-00.txt Sean Olson
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Donovan, Steven R. (MCI)
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Patrice Calhoun
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Dean Willis
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Douglas Clowes
- RE: RE: draft-ietf-mmusic-sip-session-timer-00.txt Donovan, Steven R. (MCI)
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Donovan, Steven R. (MCI)
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Donovan, Steven R. (MCI)
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Patrice Calhoun
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Patrice Calhoun
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Dean Willis
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Patrice Calhoun
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Jonathan Rosenberg
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Douglas Clowes
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Jerome Privat
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Patrice Calhoun
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Jonathan Rosenberg
- Re: draft-ietf-mmusic-sip-session-timer-00.txt John Hearty
- Re: draft-ietf-mmusic-sip-session-timer-00.txt John Hearty
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Lewis McCarthy
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Jonathan Rosenberg
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Dean Willis
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Jonathan Rosenberg
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Dean Willis
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Jonathan Rosenberg
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Aishling
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Henning Schulzrinne
- RE: draft-ietf-mmusic-sip-session-timer-00.txt Dean Willis
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Mark Handley
- Re: draft-ietf-mmusic-sip-session-timer-00.txt Henning Schulzrinne
- clients and servers Scott Petrack