[jdev] last presence confusion

Justin Karneges justin-keyword-jabber.093179 at affinix.com
Sat Dec 22 14:23:38 CST 2007

On Thursday 20 December 2007 2:52 pm, Peter Saint-Andre wrote:
>    2.  Else, if the contact has no available resources, the server MUST
>        either (1) reply to the presence probe by sending to the user the
>        full XML of the last presence stanza of type "unavailable"
>        received by the server from the contact, or (2) not reply at all.
> So a nice server will return the last unavailable presence information
> (with a Delayed Delivery flag), thus obviating the need for a flood of
> jabber:iq:last requests.

The problem is that the server might choose the second option, which is to not 
reply at all, and a client cannot know the difference between a slow server 
or a no-reply server.  Thus, the client still has to make a decision to send 
iq:last to everyone or to no one.

How about emphasizing the first option as a SHOULD?  This would hopefully 
encourage new servers to always reply, while not causing existing servers to 
become non-compliant.


More information about the JDev mailing list