Old thread alert!
On 9/18/11 9:48 PM, Justin Karneges wrote:
> On Sunday, September 18, 2011 09:19:54 AM Tomasz Sterna wrote:
>> Quoting from RFC6121:
>> 4.3.2. Server Processing of Inbound Presence Probe
>> "If there is a resource matching the full JID and the probing entity has
>> authorization via a presence subscription to see the contact's presence,
>> then the server MUST return an available presence notification, which
>> SHOULD communicate only the fact that the resource is available (not
>> detailed information such as the <show/>, <status/>, <priority/>, or
>> presence extensions)."
>>
>> May I ask what is the rationale behind this?
>> Why the server should not answer with the presence stanza of the probed
>> resource?
>
> I believe this is to ensure consistency with section 4.6.6. Basically, if
> you
> are probing a full JID then it means you're checking on a known session.
> Whether the user is in your roster (4.3.2) or not (4.6.6), the response
> should
> be the same.
>
> The meaning of these empty presence stanzas is a little funky. I think it's
> supposed to mean "the presence is unchanged since the last one sent". As far
> as I can tell this conflicts with the fact that an empty presence stanza
> already has meaning ("online") but perhaps in most modern client
> implementations there is at least some other element like <c> in there to
> ensure distinction.
At the time of writing RFC 6121, we thought there was a good reason for
the empty presence stanza (essentially: "yep, that resource is still
online"), but now I'm not so sure. Something to revisit when working on
6121bis. :)
Peter
--
Peter Saint-Andre
https://stpeter.im/
