This scenario is used when one would like to use digest authentication with Asterisk.
You will have to use regular SIP account like User=878xxxxxxx and password=xxxxxxxx.
In this scenarios Asterisk configuration should be a bit more complex.
register => 878xxxxx:passwordxxxx@sip_proxy/my_incoming_extension
useragent => PBX
Note, that it is important to set useragent parameter in [general] section as shown above, because otherwise our system will try to apply ip authentication instead
of digest. ‘register’ parameter in [general] section configures what to do with the incoming calls, in the example above such calls will be sent to context my_incoming_extension.