[OpenSIPS-Devel] pres_rules: Does presence_xml uses "sphere" element?

Iñaki Baz Castillo ibc at aliax.net
Tue Jul 14 16:24:46 CEST 2009


2009/7/14 Iñaki Baz Castillo <ibc at aliax.net>:
> So the presence agent should check if the current sphere value for the
> presentity matches the sphere value in the rule conditions.
> Of course this is really complex since there could be multiple PUBLISH
> at the same time, each one with different "sphere" value.
>
> For me it's too much "exotic", but does OpenSIPS consider it?


RFC 5025:

---------------------------------------------
3.1.2.  Sphere

   The <sphere> element is defined in [8].  However, each application
   making use of the common policy specification needs to determine how
   the presence server computes the value of the <sphere> to be used in
   the evaluation of the condition.

   To compute the value of <sphere>, the presence agent examines all
   published presence documents for the presentity.  If at least one of
   them includes the <sphere> element [9] as part of the person data
   component [10], and all of those containing the element have the same
   value for it, which is the value used for the <sphere> in presence
   policy processing.  If, however, the <sphere> element was not present
   in any of the published documents, or it was present but had
   inconsistent values, its value is considered undefined in terms of
   presence policy processing.

   Care must be taken in using <sphere> as a condition for determining
   the subscription handling.  Since the value of <sphere> changes
   dynamically, a state change can cause a subscription to be suddenly
   terminated.  The watcher has no way to know, aside from polling, when
   their subscription would be reinstated as the value of <sphere>
   changes.  For this reason, <sphere> is primarily useful for matching
   on rules that define transformations.
------------------------------


Could I know what does the last phrase mean?:

  "<sphere> is primarily useful for matching  on rules that define
transformations."





-- 
Iñaki Baz Castillo
<ibc at aliax.net>



More information about the Devel mailing list