AudioCodes Mediant 1000B User Manual page 486

Note: When using a proxy server, it is unnecessary to configure routing rules in the
Tel-to-IP Routing table, unless you require one of the following:
•
Fallback (alternative) routing when communication with the proxy server fails.
•
IP security, whereby the device routes only received calls whose source IP
addresses are configured in the table. IP security is enabled using the
SecureCallsFromIP parameter.
•
Filter Calls to IP feature: the device checks the table before a call is routed to the
proxy server. However, if the number is not allowed, i.e., the number is not
specified in the table or a Call Restriction (see below) routing rule is configured,
the call is rejected.
•
Obtain different SIP URI host names (per called number).
•
Assign IP Profiles to calls.
•
For the table to take precedence over a proxy server for routing calls, you need to
configure the PreferRouteTable parameter to 1. The device checks the
'Destination IP Address' field in the table for a match with the outgoing call; a
proxy is used only if a match is not found.
In addition to normal Tel-to-IP routing, this table supports the following features:

Least Cost Routing (LCR): If the LCR feature is enabled, the device searches the
routing table for matching routing rules and then selects the one with the lowest call
cost. The call cost of the routing rule is done by assigning it a Cost Group. For
configuring Cost Groups, see 'Least Cost Routing' on page 259. If two routing rules
have identical costs, the rule appearing higher up in the table (i.e., first-matched rule)
is used. If a selected route is unavailable, the device uses the next least-cost routing
rule. However, even if a matched rule is not assigned a Cost Group, the device can
select it as the preferred route over other matched routing rules with Cost Groups,
according to the optional, default LCR settings configured by the Gateway Routing
Policy (see 'Configuring a Gateway Routing Policy Rule' on page 499).

Call Forking: If the Tel-to-IP Call Forking feature is enabled, the device can send a
Tel call to multiple IP destinations. An incoming Tel call with multiple matched routing
rules (e.g., all with the same source prefix numbers) can be sent (forked) to multiple IP
destinations if all these rules are configured with a Forking Group. The call is
established with the first IP destination that answers the call.

Call Restriction: Calls whose matching routing rule is configured with the destination
IP address of 0.0.0.0 are rejected.

Always Use Routing Table: Even if a proxy server is used, the SIP Request-URI
host name in the outgoing INVITE message is obtained from this table. Using this
feature, you can assign a different SIP URI host name for different called and/or
calling numbers. This feature is enabled using the AlwaysUseRouteTable parameter.

IP Profiles: IP Profiles can be assigned to destination addresses (also when a proxy
is used).

Alternative Routing (when a proxy isn't used): An alternative IP destination
(alternative routing rule) can be configured for specific calls ("main" routing rule).
When the "main" route fails (e.g., busy), the device can send the call to the alternative
route. 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) as the "main" routing rule, but
assigned with different destination IP addresses. Instead of an IP address, you can
use an FQDN to resolve into two IP addresses.
User's Manual
Mediant 1000B Gateway and E- SBC
486 Document #: LTRT-27044