| The Error-Info header field provides a pointer to additional information
about the error status response.
SIP UACs have user interface capabilities ranging from pop-up windows and
audio on PC softclients to audio-only on "black" phones or endpoints
connected via gateways. Rather than forcing a server generating an error
to choose between sending an error status code with a detailed reason
phrase and playing an audio recording, the Error-Info header field allows
both to be sent. The UAC then has the choice of which error indicator to
render to the caller.
A UAC MAY treat a SIP or SIPS URI in an Error-Info header field as if it
were a Contact in a redirect and generate a new INVITE, resulting in a
recorded announcement session being established. A non-SIP URI MAY be
rendered to the user.
Examples:
SIP/2.0 404 The number you have dialed is not in service
Error-Info: sip:not-in-service-recording@atlanta.com
author: BEA Systems, NIST version: 1.2 |