If you don't want to register a line but you need credentials when calling you can:
1. Set the line in accfile.conf (username and password) but don't set the registrar
2. When calling set the sip target and the line
accfile.conf:
[user]
protocol=sip
username=my_user
password=my_password
regexroute.conf:
[default]
match_rule=sip/sip:number@ip.address;line=user
If challenged, sip will use 'user' line credentials to authenticate.
This way you don't need to register an account to server to use its credentials.
