3Com VCX v7111 User Manual page 69

Parameter
Enable History-Info Header
[EnableHistoryInfo]
®
3Com VCX V7111 VoIP Gateway User Guide
Description
Enables usage of the History-Info header. Valid options include:
[0] = Disable (default)
[1] = Enable
UAC Behavior:
Initial request: The History-Info header is equal to the Request
URI. If a PSTN Redirect number is received, it is added as an
additional History-Info header with an appropriate reason.
Upon receiving the final failure response, the gateway copies the
History-Info as is, adds the reason of the failure response to the
last entry, and concatenates a new destination to it (if an
additional request is sent). The order of the reasons is as
follows:
1. Q.850 Reason
2. SIP Reason
3. SIP Response code
Upon receiving the final (success or failure) response, the
gateway searches for a Redirect reason in the History-Info (that
is, 3xx/4xx SIP Reason). If found, it is passed to ISDN,
according to the following table:
SIP Reason Code
302 – Moved Temporarily
408 – Request Timeout
480 – Temporarily
Unavailable
487 – Request Terminated
486 – Busy Here
600 – Busy Everywhere
If history reason is a Q.850 reason, it is translated to the SIP
reason (according to the SIP-ISDN tables) and then to ISDN
Redirect reason according to the table above.
UAS Behavior:
History-Info is sent in the final response only.
Upon receiving a request with History-Info, the UAS checks the
policy in the request. If 'session', 'header', or 'history' policy tag is
found, the (final) response is sent without History-Info. Otherwise, it
is copied from the request.
ISDN Redirecting Reason
Call Forward Universal (CFU)
Call Forward No Answer (CFNA)
Call Forward Busy (CFB)
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