SIP VoIP 3.1 device (such as the Nokia N8, E7, or C7), you need to configure both the native SIP profile and the advanced VoIP settings application. AltoTelecom Step 1: Create a SIP Profile
User name: Your SIP Extension/ID.
Symbian 3 v1.0 had a notoriously weak NAT hole-punching mechanism. Under Advanced settings: sip voip 3 1 settings symbian 3 v1 0 en full
User Name & Password: Enter your specific SIP account credentials. Step 3: Advanced VoIP Tuning (The v1.0 App)
sip:username@sip.provider.comConclusion
Note: If "SIP settings" is missing, your product code firmware has disabled VOIP. You must flash to a generic EURO1 or APAC1 firmware.
Once the profile is created, open the SIP VoIP Settings app from your Applications folder. Enable 3G Calling Open the app and select VoIP Services. Choose your created profile and go to Profile Settings. Find Allow VoIP over WCDMA (or AWCDMA) and set it to On. Optimize Audio Quality SIP VoIP 3
The foundational connection is established in the system settings: