Realm for internal and external extension

after installing freepbx, having it configured internally (home), with a spa-3102 for pstn and a pap2t-na for extensions, i also configured one extension to use my nokia n95 mobile as a cordless (wireless) softphone (with the advantage of using the bluetooth headset).
All is working perfectly.
Now i want to extend the benefits and want to use the mobile also as an external extension (when travelling and having access to wifi spots).
I configured sip_nat.conf, dyndns, etc… but when creating te sip account on my mobile, i can not do it because the userid and password must be the same for the given realm.
internally, i use userid = extension #@192.168.80.xx and password = extension # , but for external use, i must use userid = extension #@FQDN and password = extension #.
The default realm is asterisk (did not even have the entry in the sip.conf file).


  1. can i use more than ONE realm, one for internal network and one for the external network?
  2. how can i increase the security for access use (recomendations are very welcome)?

Thx in advance,


P.S. I do have another question concerning spa-3102 and pap2t-na for standalone use (no asterisk or computer), for creating an extension between two homes, one having pstn line and dsl and the other with dsl only. If someone can give me a hint, i would appreciate.

No comments? Impossible to do?