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RE: [Sip] Question about Poll: Proposal relating to keepalive, TCP, and UDP usage in draft-ietf-sip-outbound
Hi,
I think that proxies should support both TCP and UDP.
Regards,
Christer
> -----Original Message-----
> From: Erkki.Koivusalo at nokia.com [mailto:Erkki.Koivusalo at nokia.com]
> Sent: 2. tammikuuta 2007 9:41
> To: fluffy at cisco.com
> Cc: sip at ietf.org; audet at nortel.com
> Subject: RE: [Sip] Question about Poll: Proposal relating to
> keepalive, TCP,and UDP usage in draft-ietf-sip-outbound
>
>
> Hi,
>
> While my email contained a lot of questions for you rather
> than a clear proposal I am not sure if we interpret each
> others opinion well enough to say we agree. Anyway to clarify
> my opinion - I agree with the proposal given for the poll:
>
> > Proposal 1: Make CRLF the only keepalive mechanism for TCP and TLS
> > over TCP flow (retain STUN for UDP flows).
> >
> > Proposal 2: Make outbound registrations over UDP flows optional for
> > UAs.
> >
> > Proposal 3: Include (in Outbound) the statement that its is
> > RECOMMENDED that the outbound-proxy-set is configured to result in
> > registrations over TCP or TLS whenever the UA can't accept incoming
> > TCP flows.
>
> Do you agree with that ?
>
> As a summary what that would mean in terms of deployments:
>
> - Every Outbound compliant (UA or proxy) implementation MUST
> support TCP but MAY support UDP too.
>
> - It will be up to the deployment to select whether TCP or UDP
> (or even both) shall be used for that specific deployment.
> Supporting UDP only would have known limitations and it would
> also mean that TCP-only implementations could not be used for
> that deployment.
>
> Erkki
>
> >--From sip-bounces at ietf.org Fri Jan 05 07:29:49 2007
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Subject: RE: [Sip] Question about Poll: Proposal relating to keepalive, TCP,
and UDP usage in draft-ietf-sip-outbound
Date: Fri, 5 Jan 2007 13:29:22 +0100
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Thread-Topic: [Sip] Question about Poll: Proposal relating to keepalive, TCP,
and UDP usage in draft-ietf-sip-outbound
Thread-Index: AccsdT4QU8BeWkSzROe/cOROp04J5wByuXCAAKBPpkAFrom: "Christer Holmberg \(JO/LMF\)" <christer.holmberg at ericsson.com>
To: <Erkki.Koivusalo at nokia.com>,
<fluffy at cisco.com>
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Hi,
I think that proxies should support both TCP and UDP.
Regards,
Christer
> -----Original Message-----
> From: Erkki.Koivusalo at nokia.com [mailto:Erkki.Koivusalo at nokia.com]
> Sent: 2. tammikuuta 2007 9:41
> To: fluffy at cisco.com
> Cc: sip at ietf.org; audet at nortel.com
> Subject: RE: [Sip] Question about Poll: Proposal relating to
> keepalive, TCP,and UDP usage in draft-ietf-sip-outbound
>
>
> Hi,
>
> While my email contained a lot of questions for you rather
> than a clear proposal I am not sure if we interpret each
> others opinion well enough to say we agree. Anyway to clarify
> my opinion - I agree with the proposal given for the poll:
>
> > Proposal 1: Make CRLF the only keepalive mechanism for TCP and TLS
> > over TCP flow (retain STUN for UDP flows).
> >
> > Proposal 2: Make outbound registrations over UDP flows optional for
> > UAs.
> >
> > Proposal 3: Include (in Outbound) the statement that its is
> > RECOMMENDED that the outbound-proxy-set is configured to result in
> > registrations over TCP or TLS whenever the UA can't accept incoming
> > TCP flows.
>
> Do you agree with that ?
>
> As a summary what that would mean in terms of deployments:
>
> - Every Outbound compliant (UA or proxy) implementation MUST
> support TCP but MAY support UDP too.
>
> - It will be up to the deployment to select whether TCP or UDP
> (or even both) shall be used for that specific deployment.
> Supporting UDP only would have known limitations and it would
> also mean that TCP-only implementations could not be used for
> that deployment.
>
> Erkki
>
> >-----Original Message-----
> >From: ext Cullen Jennings [mailto:fluffy at cisco.com]
> >Sent: 31.December.2006 02:48
> >To: Koivusalo Erkki (Nokia-TP-MSW/Helsinki)
> >Cc: audet at nortel.com; sip at ietf.org
> >Subject: Re: [Sip] Question about Poll: Proposal relating to
> keepalive,
> >TCP,and UDP usage in draft-ietf-sip-outbound
> >
> >
> >It took me some time to parse through this but sounds like you and I
> >are in 100% agreement on what an acceptable solution would look like.
> >
> >
> >On Dec 20, 2006, at 12:18 AM, <Erkki.Koivusalo at nokia.com>
> ><Erkki.Koivusalo at nokia.com> wrote:
> >
> >>
> >> Hi Cullen,
> >>
> >>>> Many PSTN gateways and Softswitches always send large
> INVITEs for
> >>>> example, and they will always fragment. And I might add
> that many
> >>>> very popular NAT/routers don't support UDP fragmentation.
> >>>
> >>> Hmm - I wish we had better specifics here - I will point
> out there
> >>> are millions of endpoints on well known residential
> endpoints that
> >>> are working through NATs and connected to PSTN gw and
> softwswiches
> >>> that are working over UDP.
> >>
> >> If so, then how would those endpoints get any benefit from
> Outbound ?
> >> What would be the value added for those deployments if those
> >endpoints
> >> would be changed as Outbound UDP compliant endpoints ? Multiple
> >> registration support and new types of keepalive messages i.e. some
> >> added reliability ?
> >>
> >> But if those endpoints and proxies anyway have to be
> either upgraded
> >> or replaced for Outbound, then why couldn't that upgrade cover TCP
> >> support as well ? What is the ultimate benefit for using
> UDP instead
> >> of TCP for those deployments ?
> >>
> >>> Uh, no - I was saying that outbound over UDP is usable in
> >cases where
> >>> the policy is to reject messages that are too large for
> UDP. I agree
> >>> that limits the functionality of the communications with
> the UA that
> >>> registered over this UDP only network but that was that
> deployments
> >>> choice.
> >>>
> >>> Note what I am talking about here is all about
> deployments using TCP
> >>> or UDP. I don't mind about if a UA has to implement both.
> >>
> >> Please remember that the proposal that you do not agree
> with was like
> >> this:
> >>
> >>> Proposal 2: Make outbound registrations over UDP flows
> optional for
> >>> UAs.
> >>
> >> Outbound over UDP would still be possible and probably
> supported by
> >> those UA vendors who get significant gain for it. But some UAs
> >> targetting to other deployments could just opt to support TCP.
> >> What is wrong with that ?
> >>
> >> If it is the deployments choice to limit the functionality of the
> >> communications with the UA registered, why could it not be
> possible
> >> for the specific closed deployments to administratively (or
> >> technically)
> >> limit the deployed UAs to be such that implement UDP ? Why
> would you
> >> mandate ALL the implemented UAs to support UDP for
> Outbound ? Those
> >> deployments could just tell the users not to aqcuire any UAs which
> >> only support Outbound with TCP, if the proxies (or
> operator policy)
> >> does not support TCP (or does not support persistent TCP
> >connections).
> >>
> >>>> You mean a UA will open two connections, one for UDP and another
> >>>> for TCP? I fail to see why on earth anybody would do
> this instead
> >>>> of just using a single TCP
> >connection.
> >>>
> >>> I think the folks that favor these approach would use a
> scheme where
> >>> the UDP connection was long lived and the TCP connection
> was short
> >>> lived for the large messages. The advantages of this
> would be to get
> >>> the scaleability and reliability schemes that are easier
> >with UDP yet
> >>> still be able to do large messages.
> >>
> >> Please remember the Outbound draft does make such a scheme
> possible !
> >> If the UA does NOT have a long lived persistent TCP connection
> >> available---Original Message-----
> >From: ext Cullen Jennings [mailto:fluffy at cisco.com]
> >Sent: 31.December.2006 02:48
> >To: Koivusalo Erkki (Nokia-TP-MSW/Helsinki)
> >Cc: audet at nortel.com; sip at ietf.org
> >Subject: Re: [Sip] Question about Poll: Proposal relating to
> keepalive,
> >TCP,and UDP usage in draft-ietf-sip-outbound
> >
> >
> >It took me some time to parse through this but sounds like you and I
> >are in 100% agreement on what an acceptable solution would look like.
> >
> >
> >On Dec 20, 2006, at 12:18 AM, <Erkki.Koivusalo at nokia.com>
> ><Erkki.Koivusalo at nokia.com> wrote:
> >
> >>
> >> Hi Cullen,
> >>
> >>>> Many PSTN gateways and Softswitches always send large
> INVITEs for
> >>>> example, and they will always fragment. And I might add
> that many
> >>>> very popular NAT/routers don't support UDP fragmentation.
> >>>
> >>> Hmm - I wish we had better specifics here - I will point
> out there
> >>> are millions of endpoints on well known residential
> endpoints that
> >>> are working through NATs and connected to PSTN gw and
> softwswiches
> >>> that are working over UDP.
> >>
> >> If so, then how would those endpoints get any benefit from
> Outbound ?
> >> What would be the value added for those deployments if those
> >endpoints
> >> would be changed as Outbound UDP compliant endpoints ? Multiple
> >> registration support and new types of keepalive messages i.e. some
> >> added reliability ?
> >>
> >> But if those endpoints and proxies anyway have to be
> either upgraded
> >> or replaced for Outbound, then why couldn't that upgrade cover TCP
> >> support as well ? What is the ultimate benefit for using
> UDP instead
> >> of TCP for those deployments ?
> >>
> >>> Uh, no - I was saying that outbound over UDP is usable in
> >cases where
> >>> the policy is to reject messages that are too large for
> UDP. I agree
> >>> that limits the functionality of the communications with
> the UA that
> >>> registered over this UDP only network but that was that
> deployments
> >>> choice.
> >>>
> >>> Note what I am talking about here is all about
> deployments using TCP
> >>> or UDP. I don't mind about if a UA has to implement both.
> >>
> >> Please remember that the proposal that you do not agree
> with was like
> >> this:
> >>
> >>> Proposal 2: Make outbound registrations over UDP flows
> optional for
> >>> UAs.
> >>
> >> Outbound over UDP would still be possible and probably
> supported by
> >> those UA vendors who get significant gain for it. But some UAs
> >> targetting to other deployments could just opt to support TCP.
> >> What is wrong with that ?
> >>
> >> If it is the deployments choice to limit the functionality of the
> >> communications with the UA registered, why could it not be
> possible
> >> for the specific closed deployments to administratively (or
> >> technically)
> >> limit the deployed UAs to be such that implement UDP ? Why
> would you
> >> mandate ALL the implemented UAs to support UDP for
> Outbound ? Those
> >> deployments could just tell the users not to aqcuire any UAs which
> >> only support Outbound with TCP, if the proxies (or
> operator policy)
> >> does not support TCP (or does not support persistent TCP
> >connections).
> >>
> >>>> You mean a UA will open two connections, one for UDP and another
> >>>> for TCP? I fail to see why on earth anybody would do
> this instead
> >>>> of just using a single TCP
> >connection.
> >>>
> >>> I think the folks that favor these approach would use a
> scheme where
> >>> the UDP connection was long lived and the TCP connection
> was short
> >>> lived for the large messages. The advantages of this
> would be to get
> >>> the scaleability and reliability schemes that are easier
> >with UDP yet
> >>> still be able to do large messages.
> >>
> >> Please remember the Outbound draft does make such a scheme
> possible !
> >> If the UA does NOT have a long lived persistent TCP connection
> >> available, there is no way for the proxy to get the UA to
> open such
> >> connection or for the proxy itself open such a TCP
> connection towards
> >> the UA via the NAT when a large message arrives destined
> to the UA.
> >> So if the UA does not keep the TCP connection open all the
> time, it
> >> has to live with the limitation of not being able to receive SIP
> >> requests bigger than MTU if the NAT discards fragmented
> UDP packets.
> >>
> >> P.S. Actually there is such a mechanism for that specified in Marc
> >> Petit-Huguenin's I-D "Preventing Fragmentation for Client
> Initiated
> >> Connections in the Session Initiation Protocol (SIP)" -
> but that is
> >> not within the baseline Outbound spec and there is no normative
> >> binding between those specs either.
> >>
> >> Regards,
> >>
> >> Erkki
> >
> >
>
> _______________________________________________
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> This list is for NEW development of the core SIP Protocol Use
> sip-implementors at cs.columbia.edu for questions on current sip
> Use sipping at ietf.org for new developments on the application of sip
>
_______________________________________________
Sip mailing list https://www1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use sip-implementors at cs.columbia.edu for questions on current sip
Use sipping at ietf.org for new developments on the application of sip