Pstn Fallback; Alternative Routing For Ip-To-Tel Calls; Alternative Routing To Trunk Upon Q.931 Call Release Cause Code - AudioCodes Mediant 500L User Manual

2. From the '3xx Use Alt Route Reasons' drop-down list, select the required handling.
Figure 24-10: Enabling Alternative Routing for SIP 3xx with Multiple Contacts
3. Click Apply.
Note: If a SIP 401 or 407 response is received from a contact, the device does not
try to redirect the call to the next contact. Instead, the device continues with the
regular authentication process, as indicated by these response types.

24.4.5 PSTN Fallback

The PSTN Fallback feature enables the device to re-route a Tel-to-IP call to the legacy
PSTN using one of its trunks if the IP destination is unavailable. For example, if poor voice
quality is detected over the IP network, the device attempts to re-route the call to the
PSTN.
The following procedure describes how to configure alternative Tel-to-IP routing to the
PSTN.

To configure alternative Tel-to-IP routing to the PSTN:
1. In the Tel-to-IP Routing table (see ''Configuring Tel-to-IP Routing Rules'' on page
509), configure an alternative routing rule with the same call matching characteristics
(e.g., phone number destination) as the "main" routing rule, but where the destination
is the IP address of the device itself.
2. In the IP-to-Tel Routing table (see ''Configuring IP-to-Tel Routing Rules'' on page
518), configure an IP-to-Tel routing rule to route calls received from the device (i.e., its
IP address) to a specific Trunk Group connected to the PSTN. This configuration is
necessary as the re-routed call is now considered an IP-to-Tel call.
Note: The PSTN Fallback feature is applicable only to digital interfaces.
24.5

Alternative Routing for IP-to-Tel Calls

The device supports alternative IP-to-Tel call routing, as described in this section.
24.5.1 Alternative Routing to Trunk upon Q.931 Call Release Cause
Code
You can configure up to 10 ISDN Q.931 release cause codes, which if received from the
Tel side, the device routes the IP-to-Tel call to an alternative Trunk Group, if configured.
Alternative IP-to-Tel routing rules are configured in the IP-to-Tel Routing table. These rules
must be configured anywhere below the "main" routing rule and with identical matching
characteristics (e.g., destination prefix number) to the "main" routing rule. The device uses
the first alternative route that is available. For more information on configuring alternative
IP-to-Tel routing rules in the IP-to-Tel Routing table, see ''Configuring IP-to-Tel Routing
Rules'' on page 518.
User's Manual
Mediant 500L Gateway & E-SBC
532 Document #: LTRT-10532