AudioCodes Mediant 500 E-SBC User Manual page 395

User's Manual
The device also supports alternative routing if the IP-to-Tel call cannot be routed to the
Trunk Group:

Routing to an Alternative Trunk Group: If a call release reason (cause) code (e.g.,
17 for User Busy) is received from the Tel side for a specific IP-to-Tel call and you
have configured this reason code in the Reasons for IP-to-Tel Alternative Routing
table, the device re-routes the call to an alternative Trunk Group if an alternative
routing rule has been configured. You must configure the alternative routing rules in
table rows (indices) that are located anywhere below the "main" routing rule. For
example, if you configure a "main" routing rule in Index 4, the alternative routing rule
can be configured in Index 6. In addition, you must configure the alternative routing
rules with identical matching characteristics (e.g., destination prefix number) to the
"main" routing rule, but assigned with different destinations (i.e., Trunk Groups). For
more information on IP-to-Tel alternative routing and for configuring call release
reasons for alternative routing, see ''Alternative Routing to Trunk upon Q.931 Call
Release Cause Code'' on page 405.

Routing to an IP Destination (i.e., Call Redirection): The device can re-route the
IP-to-Tel call to an alternative IP destination, using SIP 3xx responses. For more
information, see ''Alternative Routing to IP Destinations upon Busy Trunk'' on page
406.

Routing to an Alternative Physical Trunk Within the Same Trunk Group: The
device can re-route an IP-to-Tel call to a different physical trunk if the destined trunk
within the same Trunk Group is out of service (e.g., physically disconnected). When
the physical trunk is disconnected, the device sends the SNMP trap,
GWAPP_TRAP_BUSYOUT_LINK notifying of the out-of-service state for the specific
trunk number. When the physical trunk is physically reconnected, this trap is sent
notifying of the back-to-service state.
Notes:
•
You can configure up to three alternative routing rules per "main" routing rule in
the Inbound IP Routing table.
•
If your deployment includes calls of many different called (source) and/or calling
(destination) numbers that need to be routed to the same destination, you can
employ user-defined prefix tags to represent these numbers. Thus, instead of
configuring many routing rules, you need to configure only one routing rule using
the prefix tag as the source and destination number matching characteristics, and
a destination for the calls. For more information on prefix tags, see ''Dial Plan
Prefix Tags for IP-to-Tel Routing'' on page 559.
The following procedure describes how to configure Inbound IP Routing rules in the Web
interface. You can also configure Inbound IP Routing rules using the table ini file
parameter, PSTNPrefix or CLI command, configure voip > gw routing ip2tel-routing.
Version 6.8 395
24. Routing
Mediant 500 E-SBC