The configuration is pretty simple. See the screenshot below:
You can use whatever you want as a display name. The user name is the string
+351 followed by the number you got. The password field should pretty obvious.
The two fields that wasted most of my time where Domain (must be
voip.telepac.pt) and the
Send outbound via: must be set to
proxy with the string
This configuration is enough for me to receive and place calls. There are still some things I would like to know, like if it is possible to call my number via another SIP provider.
Although I'm using Telepac VoIP service, the SAPO VoIP service is similar (if not the exact same one), so replace
sapo.pt and you should have a working setup too (untested).
So now I have a hard phone connected to the VoIP router at the office, and a soft phone running on my Macs. With this, I now have two VoIP accounts, Skype and SIP. Next step: get a XMPP client with Jingle.
If you want to say hi, +351 302 029 050. Use a fixed line for now, it seems to be mis-configured if you use a mobile network.