Figure 3-71: Tel To Ip Routing - AudioCodes Mediant 2000 User Manual

Assign Profiles to destination addresses (also when a Proxy is used).
Alternative Routing (when a Proxy isn't used): an alternative IP destination for
telephone number prefixes is available. To associate an alternative IP address to a
called telephone number prefix, assign it with an additional entry (with a different IP
address), or use an FQDN that resolves into two IP addresses. The call is sent to the
alternative destination when one of the following occurs:
•
No ping to the initial destination is available, poor QoS (delay or packet loss,
calculated according to previous calls) is detected, or a DNS host name is not
resolved. For detailed information on Alternative Routing, refer to ''Configuring
Alternative Routing (Based on Connectivity and QoS'' on page 361.
•
A release reason defined in the 'Reasons for Alternative Tel to IP Routing' table is
received (refer to ''Reasons for Alternative Routing'' on page 188).
Alternative routing (using this table) is commonly implemented when there is no
response to an INVITE message (after INVITE retransmissions). The device then
issues an internal 408 'No Response' implicit release reason. If this reason is included
in the 'Reasons for Alternative Routing' table, the device immediately initiates a call to
the redundant destination using the next matched entry in the 'Tel to IP Routing' table.
Note that if a domain name in this table is resolved into two IP addresses, the timeout
for INVITE retransmissions can be reduced by using the parameter 'Number of RTX
Before Hotswap'.
Notes:
To configure the Tel to IP Routing table, take these 5 steps:
Open the 'Tel to IP Routing' page (Configuration tab > Protocol Configuration menu
1.
> Routing Tables submenu > Tel to IP Routing page item).
SIP User's Manual
•
If the alternative routing destination is the device itself, the call can be
configured to be routed back to the PSTN. This feature is referred to as
'PSTN Fallback', meaning that if poor voice quality occurs over the IP
network, the call is routed through the legacy telephony system (PSTN).
•
Tel-to-IP routing can be performed before or after applying the number
manipulation rules. To control when number manipulation is performed,
use the 'Tel to IP Routing Mode' (or RouteModeTel2IP ini file) parameter,
described in the table below.
•
You can also configure the 'Tel to IP Routing' table using the ini file table
parameter Prefix (refer to ''Number Manipulation and Routing
Parameters'' on page 313).
Figure 3-71: Tel to IP Routing Page
176
Mediant 2000
Document #: LTRT-68808