Subject: [Stox] Communication between STOX-capable and non-STOX-capable entities

From: Matt Ryan <[email-masked]>
Date: Mon, 19 May 2014 20:36:17 -0600

Should a STOX-capable server be able to communicate with a
non-STOX-capable server, so long as the communication is started by
the STOX-capable server?  Is this among the current goals of the WG?

Sorry if this has been covered - but this particular point remains
unclear to me despite numerous readings through draft-ietf-stox-core
and some of the other supporting drafts.

Let me provide a simple example to explain what I mean.

Suppose an XMPP client initiates a chat to a user that happens to be a
SIP client user.  Per draft-ietf-stox-chat, this request flows through
the XMPP Server which determines that the message is targeted to a SIP
user, and then invokes its own XMPP-to-SIP Gateway to translate the
request to a SIP request and send that request on to the appropriate
SIP server.

So far, the XMPP Server knows that the target user is a SIP user, but
does not know anything about the SIP Server capabilities other than
that it is (presumably) a SIP server.  Importantly, the XMPP Server
does not know whether the SIP Server also supports a SIP-to-XMPP gateway.

This is where my question comes.  Given the described XMPP Server with
a corresponding XMPP-to-SIP gateway, is it meant to be the case that
this XMPP Server should be able to communicate with any valid SIP
server, so long as the conversation is initiated by the XMPP Server?

This is an important point because it has direct impact on several of
our current drafts.

- -- 
Matt Ryan
Code Slinger  |  Jive Communications, Inc.
Jive.com  |  [email-masked]

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From: Saúl Ibarra Corretgé <[email-masked]>
Date: Wed, 28 May 2014 14:37:37 +0200

Hi Matt,

On May 20, 2014, at 4:36 AM, Matt Ryan wrote:

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The idea is that a STOX capable infrastructure is transparent to others. To the eyes of the world,  given domain, say example.com has SRV records for SIP and XMPP. The fact that there is an actual gateway handling the traffic and doing some translations is a detail of that infrastructure. So a non-STOX server should be able to communicate with a STOX server just fine.

Regards,

--
Saúl Ibarra Corretgé
AG Projects

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From: Peter Saint-Andre <[email-masked]>
Date: Thu, 29 May 2014 06:46:52 -0600

> The idea is that a STOX capable infrastructure is transparent to others. To the eyes of the world,  given domain, say example.com has SRV records for SIP and XMPP. The fact that there is an actual…

+1

Peter

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From: Matt Ryan <[email-masked]>
Date: Thu, 29 May 2014 08:48:30 -0600

Saúl and Peter, thanks for your input on my question.

I agree that this is the approach we should take.  This direction is
supported by RFC 7427 (previously draft-ietf-stox-core) where the
responsibility for determining the format for communication and
translating if required is put upon the sending server and it's
accompanying gateway, and not upon the receiving server.

Because of this, I have further concerns with draft-ietf-stox-chat-06
as well as with draft-ietf-stox-groupchat-04.  I will enumerate these
each separately in their own review emails.  But in summary, the
concerns are that the examples given in these drafts show the gateways
on both sides of communication as being involved in exchanges where
they should not be required, and that showing the involvement of both
gateways gives the impression that both ARE required.

In other words, it does not emphasize the point that STOX-capable
servers must be able to communicate effectively with non-STOX-capable
servers, which it seems we agree is important.

On 5/29/14, 6:46 AM, Peter Saint-Andre wrote:
>>> -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512
>>> 
>>> non-STOX-capable server, so long as the communication is 
>>> started by the STOX-capable server?  Is this among the current
>>>  goals of the WG?
>>> 
>>> Sorry if this has been covered - but this particular point 
>>> remains unclear to me despite numerous readings through 
>>> draft-ietf-stox-core and some of the other supporting drafts.
>>> 
>>> 
>>> Suppose an XMPP client initiates a chat to a user that happens
>>>  to be a SIP client user.  Per draft-ietf-stox-chat, this 
>>> request flows through the XMPP Server which determines that the
>>> message is targeted to a SIP user, and then invokes its own
>>> XMPP-to-SIP Gateway to translate the request to a SIP request
>>> and send that request on to the appropriate SIP server.
>>> 
>>> So far, the XMPP Server knows that the target user is a SIP 
>>> user, but does not know anything about the SIP Server 
>>> capabilities other than that it is (presumably) a SIP server. 
>>> Importantly, the XMPP Server does not know whether the SIP 
>>> Server also supports a SIP-to-XMPP gateway.
>>> 
>>> 
>>> This is where my question comes.  Given the described XMPP 
>>> Server with a corresponding XMPP-to-SIP gateway, is it meant to
>>> be the case that this XMPP Server should be able to communicate
>>> with any valid SIP server, so long as the conversation is
>>> initiated by the XMPP Server?
>>> 
>>> 
>>> This is an important point because it has direct impact on 
>>> several of our current drafts.
>>> 
>> 
>> The idea is that a STOX capable infrastructure is transparent to 
>> others. To the eyes of the world,  given domain, say example.com
>> has SRV records for SIP and XMPP. The fact that there is an
>> actual gateway handling the traffic and doing some translations
>> is a detail of that infrastructure. So a non-STOX server should
>> be able to communicate with a STOX server just fine.
> 
> +1
> 
> Peter
> 
> 

- -- 
Matt Ryan