The SIP setting is easy ...
first u creat a new profile .. call it as u wish
then in public user name : SIP:[email protected]
then proxy : realm is any name as well
user name : is the the username u crteated with the provider and loaded the cash in .
then password .

u remain with register server :

address : SIP:SIP.provider.com ( example SIP:SIP.net2phome.com)
relam : any thing
the user name and password ..
u will know if u did right by trying to call .
dial any number but don't press call then option then call .. u should see internet call in addition to voice and vedio

good luck