RE: draft-ietf-mmusic-sip-session-timer-00.txt
Pat.Calhoun@Eng.Sun.COM (Patrice Calhoun) Thu, 11 February 1999 23:26 UTC
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From: Pat.Calhoun@Eng.Sun.COM
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Date: Thu, 11 Feb 1999 15:21:44 -0800
To: "Donovan, Steven R. (MCI)" <Steven.R.Donovan@mci.com>, "'confctrl@ISI.EDU'" <confctrl@ISI.EDU>, "'iptel@lists.research.bell-labs.com'" <iptel@lists.research.bell-labs.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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> > >> -----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 >>
- 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