Interworking Sip Refer Messages - AudioCodes Mediant 1000B User Manual

User's Manual
Parameter Value
HistoryInfoMode =
Remove
DiversionMode = Add
HistoryInfoMode =
Disable
DiversionMode = Add
HistoryInfoMode =
Disable
DiversionMode = Add
HistoryInfoMode = Add
DiversionMode = Add
HistoryInfoMode =
Remove
DiversionMode = Remove

28.8.3 Interworking SIP REFER Messages

The device supports interworking of SIP REFER messages. SIP UAs may support different
versions of the REFER standard while others may not even support REFER.
This feature supports the following:

Attended, unattended, and semi-attended call transfers

Sending INVITE, REFER-notifications, BYE, PRACK and Session Timer on behalf of
peer PBXs

Advanced routing rules for the new, initiated INVITE

Forwarding early media after REFER while attempting to avoid transcoding (by
sending session update)

Interoperate with environments were different SIP UAs lack basic SIP functionality
such as re-INVITE, UPDATE, PRACK, Delayed Offer, re-INVITE without SDP

Session updates after connect to avoid transcoding
The handling of REFER can be configured for all calls, using the global parameter
SBCReferBehavior. For configuring different REFER handling options for different UAs
(i.e., IP Groups), use the IP Profile table parameter, 'SBC Remote Refer Behavior'.

Local handling of REFER: This option is used for UAs that do not support REFER.
Upon receipt of a REFER request, instead of forwarding it to the IP Group, the device
handles it locally. It generates a new INVITE to the alternative destination according to
the rules in the IP-to-IP Routing table (where the 'Call Trigger' field is set to REFER). It
is also possible to specify the IP Group that sent the REFER request, as matching
criteria for the re-routing rule in this table ('ReRoute IP Group ID' field).

Transparent handling: The device forwards the REFER with the Refer-To header
unchanged.

Re-routing through SBC: The device changes the Refer-To header so that the re-
routed INVITE is sent through the SBC application.

IP Group Name: The device sets the host part in the REFER message to the name
configured for the IP Group in the IP Group table.
Version 6.8
SIP Header Present in Received SIP Message
Not present. History-Info
converted to
Diversion.
History-Info
removed.
Diversion Not present.
converted to
History-Info.
Not present. History-Info
converted to
Diversion.
Diversion History-Info
converted to converted to
History-Info. Diversion.
Diversion removed. History-Info
removed.
503
28. SBC Overview
History-Info added to Diversion.
History-Info removed.
Diversion added to History-Info.
History-Info added to Diversion.
Headers are synced and sent.
Both removed.
Mediant 1000B Gateway & SBC