Re: [Stox] Review of -chat

Peter Saint-Andre <> Wed, 31 July 2013 14:37 UTC

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Date: Wed, 31 Jul 2013 16:37:21 +0200
From: Peter Saint-Andre <>
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Subject: Re: [Stox] Review of -chat
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On 7/30/13 4:01 PM, Saúl Ibarra Corretgé wrote:
> Hi,
> Here is my review of the -chat document.
> - What should a gateway do when it gets a message with XHTML-IM body?
> I guess send it with content-type text/html, but is there any
> translation required?

I know about the use of XHTML in XMPP, but I don't know much about the
use in SIP. Is there a profile of (X)HTML that most SIP entities implement?

> - Section 4 mentions what should happen if no formal sessions are
> used, but doesn't say anything of the opposite. Should we say that
> those are out of the scope of this specification?

Precursors to this document talked about formal chat sessions in XMPP
(XEP-0155), however no clients support that model so I remove all of
that text. The first paragraph of Section 4 reflects the earlier specs.
I think we just need to remove a few words from Section 4...

   When an MSRP client sends messages through a gateway to an XMPP
   client that does not support formal sessinos, the order of events is
   as follows.

   When an MSRP client sends messages through a gateway to an XMPP
   client, the order of events is as follows.

> - I think we should define a mapping between XMPP chatstates
> (XEP-0085) and the iscomosing indication (RFC 3994) particularly, the
> "gone" state in XMPP should trigger a BYE on the SIP side, and vice
> versa.

Could you describe a bit why you think that would be useful? (You
explained it to me in person, but I think it would be helpful to discuss
it on the list so that it's in the records of the WG. And for the record
I am pretty sure I agree with you.)

> - Should we add text to map MSRP reports to XMPP receipts (XEP-0184)?
> They do map very well semantically. Now, XEP-0184 says that the ack
> may not be sent if "The recipient simply does not wish to return a
> receipt for the content message.", which pretty much renders it
> useless. Anyway, I think we do need some text explaining how MSRP
> success and failure ports should be dealt with.

I wonder if this belongs in the stox-chat spec or in an extension document.

(And BTW XMPP message receipts can be used outside of chat sessions, so
I think it applies more broadly than the stox-chat spec.)

> - In general: we don't have any example using CPIM, not sure if we
> should say anything about it.

What do you have in mind for CPIM examples? Do you mean examples other
than MSRP, or examples with CPIM payloads?


Peter Saint-Andre