I recommend the following steps for setting up your Nokia E63 for VoIP over Wifi (and perhaps for other S60 based phones as well), for Voip.ms, the realm settings were the same as the others:

How to configure SIP profile in Nokia Eseries devices for VoIP calls?

This text is a cut-and-paste from Nokia's FAQ.

The Nokia Eseries mobile devices support SIP VoIP internet calls. This article describes a sample configuration when user authentication is enabled in the SIP proxy and registrar servers. The proxy and registrar servers are located in the same device in this sample.

Before configuring the mobile device, the following information should be obtained from the SIP service provider (some other parameter values may also need to be checked if not using the default values):

SIP proxy and registrar server address ("sip.voipservice.com" in this sample)
SIP proxy realm ("inphone.com" in this sample)
SIP registrar realm ("sip.voiceservice.com" in this sample)
User name ("1234567" in this sample for both the proxy and registrar)
User password ("1234")
Public user name ("1234567@sip.voipservice.com" in this sample)

In order to establish a VoIP call, a WLAN access point needs to be defined in the mobile device access point settings and the mobile device must be within the reach of the WLAN network.

Start the mobile device SIP configuration by going to menu Tools > Settings > Connection > Sip Settings and by creating a new SIP profile. The following parameters are defined in the profile:

Profile name: Siptest (can be freely chosen)
Service profile: IETF
Default access point: WLAN access point used for the VoIP connections
Public user name: 1234567@sip.voipservice.com (note that the public user name must be given in this format, including the domain name)
Use compression: no
Registration: when needed (set "always on" if you want the registration to occur automatically)
Use security: no
Proxy Server:
Proxy Server Address: sip.voipservice.com
Realm: inphone.com
User name: 1234567
Password: 1234
Allow loose routing: yes
Transport type: UDP
Port: 5060
Registrar:
Registrar Server Address: sip.voipservice.com
Realm: sip.voipservice.com
User name: 1234567
Password: 1234
Allow loose routing: yes
Transport type: UDP
Port: 5060

Note that the realm name is often the same for both the proxy and registrar but the name may also be different, as in this sample. If the registrar realm name is not correctly defined, the registration will fail. If the realm name of the proxy is not correct, the registration may succeed but the internet calls will fail.

When the SIP profile has been created, go to Tools > Settings > Connection > Internet tel.settings menu to create a new internet telephone profile. Select New profile with type "SIP" and set the following fields:

Name: Siptest (name can be freely chosen)
Sip profiles: select the SIP profile created above ("Siptest")

When the SIP and internet telephone profiles have been created, go to Connectivity > Internet.tel menu to connect to the service if the option "When needed" was selected in the SIP profile "Registration" parameter. If the option "Always on" was selected in the SIP profile "Registration" parameter, the SIP client will try to register automatically when it detects that the given WLAN network is accessible.

When the registration is complete, the VoIP SIP calls can be initiated in the following way:

type in the telephone number or SIP destination name
select Options > Call > Internet call

The internet calls can be set also as the default call type in the Tools > Settings > Call > Default Call Type parameter. If set as default, the internet call type doesn't need to be explicitly selected when placing the call.

Overall, the phone gives very stupid unhelpful error messages.

Nokia E63 (and E71 too?) Voip Setup SIP Problems

I kept getting "Recipient has active call restrictions", and I couldn't even find much on Google regarding this. Other people did get "Recipient has active call barrings" errors. It turned out that I had set too restrictive codec choices through my VoIP provider. In other words, I had only codecs enabled which the Nokia E63 didn't support. Once I had changed my VoIP provider to allow more codecs, problem solved!

I will say that my Blackberry had a more throught out graphical and physical user interface than the Nokia, but Blackberry locks down their devices more than Nokia :(

Now I'm getting "Address Not In Use" errors, and I think it is because I'm deregistering or something from my SIP VoIP provider, but the phone will make outgoing VoIP calls once I disconnect from SIP and then reconnect. Anyone have any tips for this one?