Subject: Re: [Stox] review: stox-im-03

From: Salvatore Loreto <[email-masked]>
Date: Tue, 24 Sep 2013 12:37:00 +0000

Thanks Peter

--Original message---
Sender: "Peter Saint-Andre" <[email-masked]>
Time: Tue Sep 24 15:35:00 EEST 2013
Cc: [email-masked], 
Subject: Re: [Stox] review: stox-im-03

On 9/24/13 12:02 AM, Salvatore Loreto wrote:
> On 9/24/13 2:45 AM, Peter Saint-Andre wrote: Hi Sal, thanks for the
> review.
> 
> On 9/20/13 4:42 AM, Salvatore Loreto wrote:
> 
>>>> my only comments is about the fact that section 3. XMPP to
>>>> SIP implies that the MESSAGE is always (and maybe can only
>>>> be) delivered over a TCP connection; RFC3428 states
>>>> 
>>>> Whenever possible, MESSAGE requests SHOULD be sent over
>>>> transports that implement end-to-end congestion control, such
>>>> as TCP or SCTP. However, SIP does not provide a mechanism to
>>>> prevent a downstream hop from sending a request over UDP.
>>>> 
>>>> so you can delivery it over UDP as well and that has also
>>>> being raised in a previous thread while talking on the
>>>> Call-ID mapping to <thread/>. Actually you will be forced to
>>>> deliver over UDP if the SIMPLE server only supports UDP.
> It's not clear to me why the XMPP-to-SIP gateway couldn't
> communicate with the SIMPLE server over UDP. Which text in Section
> 3 do you think implies that only TCP connections are supported?
>> there is not text at all, and that is the problem. When I read
>> the Section 3 and the example I got the impression that I can
>> only use TCP to forward the message on the SIP side but maybe it
>> is only me!

I doubt it is only you. :-)

Because there is no such thing as XMPP over UDP, the gateway from SIP
to XMPP will need to communicate over TCP. However, I see no reason
why the gateway from XMPP to SIP could not be "smart" and send SIP
messages over TCP or UDP depending on what the far SIP server
supports. I'll work to add some clarifying text on these points.

Peter

- -- 
Peter Saint-Andre
https://stpeter.im/

---

From: Peter Saint-Andre <[email-masked]>
Date: Tue, 24 Sep 2013 06:40:11 -0600

Oh, and this text probably belongs in the -core document, I think...

On 9/24/13 6:37 AM, Salvatore Loreto wrote:
> _______________________________________________
> stox mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/stox
> 

-- 
Peter Saint-Andre
https://stpeter.im/

---

From: Peter Saint-Andre <[email-masked]>
Date: Tue, 24 Sep 2013 20:17:57 -0600

Here is proposed text for placement at the end of Section 4
("Interdomain Federation") in the -core document:

   Because [RFC6120] specifies a binding of XMPP to TCP, a gateway from
   SIP to XMPP will need to support TCP as the underlying transport
   protocol.  By contrast, as specified in [RFC3261], either TCP or UDP
   can be used as the underlying transport for SIP messages, and a given
   SIP deployment might support only UDP; therefore, a gateway from XMPP
   to SIP might need to communicate with a SIP service using either TCP
   or UDP.

Peter

On 9/24/13 6:40 AM, Peter Saint-Andre wrote:
>> --Original message--- Sender: "Peter Saint-Andre"
>> <[email-masked]> Time: Tue Sep 24 15:35:00 EEST 2013 Cc:
>> [email-masked], Subject: Re: [Stox] review: stox-im-03
>> 
>>> On 9/24/13 2:45 AM, Peter Saint-Andre wrote: Hi Sal, thanks for
>>> the review.
>> 
>>>>>> my only comments is about the fact that section 3. XMPP
>>>>>> to SIP implies that the MESSAGE is always (and maybe can
>>>>>> only be) delivered over a TCP connection; RFC3428 states
>>>>>> 
>>>>>> transports that implement end-to-end congestion control,
>>>>>> such as TCP or SCTP. However, SIP does not provide a
>>>>>> mechanism to prevent a downstream hop from sending a
>>>>>> request over UDP.
>>>>>> 
>>>>>> so you can delivery it over UDP as well and that has
>>>>>> also being raised in a previous thread while talking on
>>>>>> the Call-ID mapping to <thread/>. Actually you will be
>>>>>> forced to deliver over UDP if the SIMPLE server only
>>>>>> supports UDP.
>>> communicate with the SIMPLE server over UDP. Which text in
>>> Section 3 do you think implies that only TCP connections are
>>> supported?
>>>> there is not text at all, and that is the problem. When I
>>>> read the Section 3 and the example I got the impression that
>>>> I can only use TCP to forward the message on the SIP side but
>>>> maybe it is only me!
>> 
>> Because there is no such thing as XMPP over UDP, the gateway from
>> SIP to XMPP will need to communicate over TCP. However, I see no
>> reason why the gateway from XMPP to SIP could not be "smart" and
>> send SIP messages over TCP or UDP depending on what the far SIP
>> server supports. I'll work to add some clarifying text on these
>> points.
>> 
>> Peter