Specifying an edge is not allowed when dialing SIP registered endpoints

Twilio SIP domains allow endpoints to register through any supported SIP edge location. When dialing a registered endpoint, Twilio will fork the call to all SIP devices registered under the same username/domain. Dialing one of your SIP domain's localized URIs (such as yourdomain.sip.ashburn.twilio.com) is not supported.

• Attempting to place a call to username@yourdomain.sip.ashburn.twilio.com, or any other edge variant (e.g. ashburn-ix, umatilla, sydney, etc.)
• Note that existing registration customers dialing yourdomain.sip.us1.twilio.com or yourdomain.sip.us1-ix.twilio.com are allowed (although this behavior is deprecated).

• Dial the global URI for your SIP domain, e.g. username@yourdomain.sip.twilio.com.