SIP: Header name is not allowed

The SIP header you asked Twilio to stamp was omitted because it is not supported on the Twilio platform.

Twilio supports extension headers beginning with an X- prefix. Your extension header name cannot begin with the prefix X-Twilio.

• SIP header name not supported on the Twilio platform.

• If your application can use a different header name, use an X- prefixed header name, e.g. if you want to use the name Customer-Info , see if your application can be configured to use X-Customer-Info instead.