AudioCodes Mediant 800B User Manual page 344

Parameter
Web: Remote REFER Behavior
CLI: sbc-rmt-refer-behavior
[IpProfile_SBCRemoteReferBehavior]
Web: Remote 3xx Behavior
CLI: sbc-rmt-3xx-behavior
[IpProfile_SBCRemote3xxBehavior]
User's Manual
Mediant 800B Gateway and E-SBC
Description
Defines the device's handling of REFER requests for this
SIP entity.

[0] Regular = (Default) Refer-To header is unchanged
and the device forwards the REFER as is.

[1] Database URL = Changes the Refer-To header so
that the re-routed INVITE is sent through the SBC:
a. Before forwarding the REFER request, the device
changes the host part to the device's IP address
and adds a special prefix ("T~&R_") to the Contact
user part.
b. The incoming INVITE is identified as a REFER-
resultant INVITE according to this special prefix.
c. The device replaces the host part in the Request-
URI with the host from the REFER contact. The
special prefix remains in the user part for regular
classification, manipulation, and routing. The
special prefix can also be used for specific routing
rules for REFER-resultant INVITEs.
d. The special prefix is removed before the resultant
INVITE is sent to the destination.

[2] IP Group Name = Sets the host part in the REFER
message to the name defined for the IP Group (in the
IP Group table).

[3] Handle Locally = Handles the incoming REFER
request itself without forwarding the REFER. The
device generates a new INVITE to the alternative
destination according to the rules in the IP-to-IP
Routing table (the 'Call Trigger' field must be set to
REFER).
Note: The corresponding global parameter is
SBCReferBehavior.
Defines the device's handling of SIP 3xx redirect
responses for this SIP entity. By default, the device's
handling of SIP 3xx responses is to send the Contact
header unchanged. However, some SIP entities may
support different versions of the SIP 3xx standard while
others may not even support SIP 3xx.
When enabled, the device handles SIP redirections
between different subnets (e.g., between LAN and WAN
sides). This is required when the new address provided by
the redirector (Redirect sever) may not be reachable by
the far-end user (FEU) located in another subnet. For
example, a far-end user (FEU) in the WAN sends a SIP
request via the device to a Redirect server in the LAN, and
the Redirect server replies with a SIP 3xx response to a
PBX in the LAN in the Contact header. If the device sends
this response as is (i.e., with the original Contact header),
the FEU is unable to reach the new destination.

[0] Transparent = (Default) The device forwards the
received SIP 3xx response as is, without changing the
Contact header (i.e.,transparent handling).

[1] Database URL = The device changes the Contact
header so that the re-route request is sent through the
device. The device changes the URI in the Contact
header of the received SIP 3xx response to its own
344 Document #: LTRT-10620