AudioCodes Mediant 1000B User Manual page 322

Parameter
Web: Remote 3xx Behavior
CLI: sbc-rmt-3xx-behavior
[IpProfile_SBCRemote3xxBeha
vior]
User's Manual
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 URI and adds a special user prefix
("T~&R_"), which is then sent to the FEU. The FEU then sends
a new INVITE to the device, which the device then sends to the
correct destination.

[2] Handle Locally = The device handles SIP 3xx responses on
behalf of the dialog-initiating UA and retries the request (e.g.,
INVITE) using one or more alternative URIs included in the 3xx
response. The device sends the new request to the alternative
destination according to the IP-to-IP Routing table (the 'Call
Trigger' field must be set to 3xx).
Notes:

When this parameter is changed from 1 to 0, new 3xx Contact
headers remain unchanged. However, requests with the special
322
Mediant 1000B Gateway & SBC
Description
Document #: LTRT-27034