AudioCodes Mediant 2000 User Manual page 153

SIP User's Manual
3.3.7.9.9 Configuring Reasons for Alternative Routing
The 'Reasons for Alternative Routing' page allows you to define up to four different call
release (termination) reasons for IP-to-Tel call releases and for Tel-to-IP call releases. If a
call is released as a result of one of these reasons, the device tries to find an alternative
route for that call.
The release reason for IP-to-Tel calls is provided in Q.931 notation. As a result of a release
reason, an alternative Trunk Group is provided. For defining an alternative Trunk Group,
refer to ''Configuring the IP to Trunk Group Routing'' on page 145.
The release reason for Tel-to-IP calls is provided in SIP 4xx, 5xx, and 6xx response codes.
As a result of a release reason, an alternative IP address is provided. For defining an
alternative IP address, refer to ''Configuring the Tel to IP Routing Table'' on page 138.
Call release reasons can be configured, for example, for the following scenarios:

IP-to-Tel calls:
other call releases that issue the default release reason (#3) (refer to the parameter
DefaultReleaseCause).

Tel-to-IP calls: when there is no response to an INVITE message (after INVITE re-
transmissions), the device issues an internal 408 'No Response' implicit release
reason.
Notes:
Version 5.8
when the destination is busy and release reason #17 is issued or for
•
The reasons for alternative routing for Tel-to-IP calls only apply when a
Proxy is not used.
•
For Tel-to-IP calls, the device sends the call to an alternative route only
after the call has failed and the device has subsequently attempted twice
to establish the call unsuccessfully.
•
You can also configure alternative routing using the ini file table
parameters AltRouteCauseTel2IP and AltRouteCauseIP2Tel (refer to
''Number Manipulation and Routing Parameters''
153
3. Web-Based Management
on page 348 ).
October 2009