On looking at your user manual
here I can see that you can connect to a WLAN (pages 96-99 of this manual). That isnt the important bit though from what I can gather. The best bit is your phone supports the Session Initiated Protocol (or SIP as mentioned here in Voxalot) over UMTS (ie your N80 must show that it's in 3G mode for this to work). Check out page 63 of the user manual.
It would seem that you just need to add a new SIP profile for each contact you wish to call (using the data on
Sipbroker the first three or four digits representing their voip providers unique 'code')
I'm sure there's more to it but maybe someone a little more technical than me can work it. I personally can't workout where to place the voxalot settings yet but maybe if you contact Nokia telling them the type of information you need to
enter they could point you in the right direction?
Best of luck
