7940/7960 SIP settings for Asterisk

Settings>Sip configuration>Line 1 Settings
Name = extension
Shortname = extension
Authentication Name = extension
Authentication Password = Password set on server
Display name = extension
Proxy Address = IP of voice server(FQDN did not work for me for some reason)
Proxy Port = default of 5060
Settings>Sip configuration
Make sure the register expires setting is set to 600. I’ve had problems where I could not receive incoming calls because this was set at the default of 3600.