[Users] several presence question

[Adrian Georgescu]

On Dec 29, 2006, at 11:47 PM, Klaus Darilion wrote:

> Hi!
>
> I read the docs of the presence module and have some question. Maybe
> someone can enlighten me ;-)
>
> 1. If I understand correctly, the pua module acts as a "UAC". Thus,  
> it can
> be used to send PUBLISH or SUBSCRIBE. I wonder what is the usecase for
> sending SUBSCRIBE? Usually, a client which sends a SUBSCRIBE receives
> subsequent NOTIFY messages. How can these NOTIFY messages be handled?

In this case is the pua module that sends Notify as responses to the  
Subscribe messages sent by the SIP UAs. For this to work the SIP UA  
must be set to use presence using a Presence agent where it send  
Publish messages and the proxy must relay all Subscribe messages to  
the presence module. The SIP UA does not send Notify in this case.

1. Presence Peer to Peer mode

SIP UAs send Subscribe/Notify between themselves. The Proxy need only  
to route these messages.

2. Presence Server mode

SIP UAs send Publish/Subscribe and both get routed to the presence  
server, which then sends Notify to the watchers validated by the XCAP  
rules. The proxy configuration must route the Subscribe messages to  
the presence server or module.

As far as I understand, these two modes seem to exclude each other,  
once you enable either mode the other cannot work so all user agents  
must obey to this topology.


Adrian