| When present in an INVITE request, the Alert-Info header field
specifies an alternative ring tone to the UAS. When present in a 180
(Ringing) response, the Alert-Info header field specifies an
alternative ringback tone to the UAC. A typical usage is for a proxy
to insert this header field to provide a distinctive ring feature.
The Alert-Info header field can introduce security risks, which are
identical to the Call-Info header field risk, see section 20.9 of
RFC3261.
In addition, a user SHOULD be able to disable this feature selectively.
This helps prevent disruptions that could result from the use of this
header field by untrusted elements.
For Example:
Alert-Info:
author: BEA Systems, NIST version: 1.2 |