AudioCodes Mediant 500 MSBR, Руководство пользователя

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Version 7.2 517 Mediant 500 MSBR
User's Manual 27. Routing
27.4.4 Alternative Routing upon SIP 3xx with Multiple Contacts
You can configure how the device handles received SIP 3xx responses that contain
multiple alternative contacts. The 3xx response indicates that the original destination is
unavailable (e.g., 301 Moved Permanently – user cannot be found) and that the call can be
redirected to alternative destinations specified in the SIP Contact headers.
Configured by the '3xx Use Alt Route Reasons' parameter, the device can handle the
receipt of 3xx responses using one of the following methods:

The device tries each contact sequentially, listed in the Contact headers, until a
successful destination is found. If a contact responds with a SIP 486 or 600, the
device does not try to redirect the call to the next contact and drops the call.

The device tries each contact sequentially, listed in the Contact headers. If a SIP 6xx
Global Failure response is received during this process (e.g., 600 Busy Everywhere),
the device does not try to redirect the call to the next contact and drops the call.

The device redirects the call to the first contact listed in the Contact header. If the
contact responds with a SIP response that is configured in the Reasons for Tel-to-IP
Alternative Routing table (see Alternative Routing Based on SIP Responses on page
514), the device tries to redirect the call to the next contact, and so on. If a contact
responds with a response that is not configured in the table, the device does not try to
redirect the call to the next contact and drops the call.

To configure handling of SIP 3xx responses with multiple contacts:
1. Open the Gateway Advanced Settings page ( Setup menu > Signaling & Media tab >
Gateway folder > Gateway Advanced Settings ).
2. From the '3xx Use Alt Route Reasons' drop-down list, select the required handling.
Figure 27-10: 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.
27.4.5 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 495),
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.