I am using a SIP provider that has provided me with a username like: [email protected] (Note this is only the username part) And has a numerical password. My Register string looks something like this: [email protected]:[email protected] But this is not working, as asterisk is only sending the first part +112223344 before the first @. My provider is adamant about having the full form of it. This is the first time I am facing this issue that is quite unusual for me. Please help.