I just got telephony from xs4all and this is the nice thing: they provide sip access to their phone system. It was a little bit trial and error but now I can use my Nokia E51 using their phone system. This post describes the correct settings.
I am using voipbusterpro as my default voip provider. They offer a SIP service which makes it possible to call with any SIP device (both soft- and hardware) you want. Recently I bought a Nokia E51 which has wifi. I wanted to make SIP phone calls over any arbitrary wifi connections with my voipbusterpro account. The only problem was setting the right settings. After a long period of trial and error I figured out the right settings.
This post shows a brief tutorial about the settings needed to setup your Nokia E51 with a Betamax account. Betamax uses a tremendous amount of different names like: 12Voip, BudgetSIP, Calleasy, DarmowyTelefon, Dialnow, Freecall, Hungarytopup, Internetcalls, Intervoip, JustVoip, LeVoip, LowRateVoip, NetAppel.fr, Nonoh, SmsListo, SparVoip, VoipBuster, VoipBusterPro, VoipCheap, VoipDiscount, Voiphit, VoipRaider, VoipStunt, VoipWise and WebCallDirect…