AudioCodes Mediant 3000, User Manual

Page: 453 / 872

Version 6.6 453 Mediant 3000
User's Manual 29. SBC Configuration
Parameter Description
Alternative Route
Options
[IP2IPRouting_ AltRoute
Options]
Determines whether this routing rule is the main routing rule or an
alternative routing rule (to the rule defined directly above it in the table).

[0] Route Row (default) = Main routing rule - the device first attempts
to route the call to this route if the incoming SIP dialog's input
characteristics matches this rule.

[1] Alt Route Ignore Inputs = If the call cannot be routed to the main
route (Route Row), the call is routed to this alternative route
regardless of the incoming SIP dialog's input characteristics.

[2] Alt Route Consider Inputs = If the call cannot be routed to the
main route (Route Row), the call is routed to this alternative route only
if the incoming SIP dialog matches this routing rule's input
characteristics.
Notes:

The alternative routing entry ( [1] or [2]) must be defined in the next
consecutive table entry index to the Route Row entry (i.e., directly
below it). For example, if Index 4 is configured as a Route Row, Index
5 must be configured as the alternative route.

For IP-to-IP alternative routing, configure alternative routing reasons
upon receipt of 4xx, 5xx, and 6xx SIP responses (see Configuring
Alternative Routing Reasons on page
453 ). However, if no response,
ICMP, or a SIP 408 response is received, the device attempts to use
the alternative route even if no entries are configured in the ‘SBC
Alternative Routing Reasons’ table.

Multiple alternative route entries can be configured (e.g., Index 1 is
the main route - Route Row - and indices 2 through 4 are configured
as alternative routes).
Cost Group
[IP2IPRouting_CostGro
up]
Assigns a Cost Group to the routing rule for determining the cost of the
call. To configure Cost Groups, see 'Configuring Cost Groups' on page
219 .
By default, no Cost Group is assigned to the rule.
29.4.4 Configuring Alternative Routing Reasons
The SBC Alternative Routing Reasons page allows you to define up to five different call
release (termination) reasons for call releases. If a call is released as a result of one of
these reasons provided in SIP 4xx, 5xx, and 6xx response codes, the device attempts to
locate an alternative route for the call. The call release reason type can be configured, for
example, when there is no response to an INVITE message (after INVITE re-
transmissions), where the device issues an internal 408 'No Response' implicit release
reason.
Release reasons can also be configured to indicate that a route for an SRD or IP Group
has reached its call admission control limit (i.e., maximum concurrent calls and/or call rate),
as set in the Admission Control table (see 'Configuring Admission Control' on page
436 ). In
such a scenario, an alternative route configured in the IP-to-IP Routing table can be used.
Alternative routing rules are configured in the IP-to-IP Routing table where the 'Alternative
Route Options' parameter is set to
Alt Route Ignore Inputs or Alt Route Consider
Inputs . For more information, see 'Configuring SBC IP-to-IP Routing' on page 446 .