32112: SIP: Invalid header value

The header you asked Twilio to stamp was omitted because it contains illegal characters in its value. Including this header would have resulting in Twilio generating a message that runs contrary to the SIP specification.

The set of legal characters for various header values is defined in RFC 3261. Twilio adheres to the criteria for "Extension Headers" specified in RFC 3261.

• If you specified headers in a SIP URI, invalid characters were most likely introduced by an escaped character. Escaped characters in SIP URIs are defined by a percent sign (%) followed by two hexadecimal digits specifying a character code.

• If you are generating SIP headers from user input, ensure your application properly accounts for non-alphanumeric characters such as punctuation and whitespace, as well as international characters.