SIP History-Info Header

The SIP History-Info Header defined in RFC 4244 provides a way of capturing any redirection information that may have occurred on a particular call. Without the SIP History-Info Header the redirecting information would be lost. The SIP History-Info Header is generated when a SIP request is re-targeted and can appear in any SIP request not associated with a dialog. The SIP History-Info header is generated by a User Agent or proxy and is passed from one entity to another through requests and responses. An example of the SIP History Header is shown below.

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