Too all people trying to use xmpp and that install openfire, just wanted to tell you that by default Issabel uses prosody, more lightweight and perfectly capable, and already integrated with issabel user system (not sip peers).
The domain is "issabel", the user is the issabel user and the password the issabel user password (again, not the sip credentials, but issabel user credentials). Any user created in issabel will be a possible user for xmpp via prosody and you can use any xmpp client to work with.
Now, the default prosody config does not enable xmpp over websokets, you might have a client that requires connection via websocket. If so, then you will need to modify the prosody.cfg.lua file to enable websockets, and possibly add the ssl certificate for it..
Enabling websockets is as simple as uncommenting the websocket line from the above mentioned file. Where it reads --"websocket" remove the double dash (signals a comment in lua). And then you might want to add some other directives that might be needed:
https_certificate = "/etc/asterisk/keys/asterisk.pem"
https_ports = { 5281 };
cross_domain_websocket = true;
cross_domain_websocket is most probably needed when using a self signed certificate or similar, where the host you use to reach the server does not match the one defined in certificates or on the server itself (the cross_domain_websocket can also be a list of valid/accepted domains, setting it to true is perhaps not good practice, but setting that the right way might be complicated/daunting depending on your network setup).
We are exploring the possibility on selecting between issabel user system and sip users for the authentication and roster in xmpp. I am currently actively working on that, but time is short and we are looking for funding so we can dedicate more time to it. https://bounty.issabel.org