Re: [reSIProcate-users] NOTIFY and PUBLISH for Presence

[Adam Roach <adam@xxxxxxxxxxx>]

Karlsson wrote:
> Hi all, a quesiton: for the presence, when to use PUBLISH and when to 
> use Notify?

From a protocol perspective, it is usually illegal to send a NOTIFY 
somewhere unless you have received a SUBSCRIBE from that same place 
(REFER is the one exception). If you use PUBLISH to send presence 
information, you need to be pretty sure that the thing you're sending it 
to is expecting it. That pretty much limits you to sending PUBLISH to 
presence servers, and never to phones (or similar devices).

The the practical guideline is that clients generally send PUBLISH to 
the presence server, and the presence server will sentd NOTIFY to 
clients that have sent it SUBSCRIBEs.

There are a bunch of exceptions to that guideline, but that's what 
you'll want to do for the most common presence server architectures most 
of the time.

/a