Alternative Routing Based On Sip Responses - AudioCodes E-SBC User Manual

CHAPTER 25 Routing
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To configure alternative Tel-to-IP routing based on IP connectivity:
1. In the Tel-to-IP Routing table (see
IP routing rules for specific calls.
2. Open the Routing Settings page (Setup menu > Signaling & Media tab > Gateway folder >
Routing > Routing Settings):
3. Under the Alternative Route group, do the following:
a. From the 'Enable Alt Routing Tel to IP' (AltRoutingTel2IPEnable) drop-down list, select
Enable to enable alternative Tel-to-IP routing based on IP connectivity.
b. From the 'Alt Routing Tel to IP Mode' drop-down list (AltRoutingTel2IPMode), configure
the IP connectivity reason for triggering alternative routing.
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c. (For Analog Interfaces Only) In the 'Alternative Routing Tone Duration' field, configure the
duration for which the device plays a tone to the Tel endpoint (for analog interfaces)
whenever an alternative route is used.
d. Enable the connectivity feature (see

Alternative Routing Based on SIP Responses

The device can perform alternative routing based on the received SIP response code (i.e., 4xx, 5xx,
6xx, or 8xx). If you have configured the response code in the Reasons for Tel-to-IP Alternative
Routing table, the device attempts to re-route the call to an alternative destination, if configured.
You can configure up to 10 SIP response codes in the Reasons for Tel-to-IP Alternative Routing
table.
Typically, the device performs alternative routing when there is no response at all to an INVITE
message. This is done after a user-defined number of INVITE re-transmissions, configured by the
SIPMaxRtx parameter. In such a scenario, the device issues itself the SIP response code 408
(Request Timeout). You can also configure the device to perform alternative routing for the
following proprietary response codes that are issued by the device itself:
■ 805 IP Profile Call Limit: The device generates this response code when Call Admission
Control (CAC) limits are exceeded for an IP Group. The CAC rules are configured in the IP
Profiles table (see
(Temporarily Unavailable) response to the SIP entity.
Connectivity: Alternative routing is performed if SIP OPTIONS message to the initial
destination fails
QoS: Alternative routing is performed if poor QoS is detected. QoS is quantified
according to delay and packet loss calculated according to previous calls.
Both (above)
Configuring IP
Mediant 1000 Gateway & E-SBC | User's Manual
Configuring Tel-to-IP Routing
IP Destinations Connectivity
Profiles). When this occurs, the device sends a SIP 480
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Rules), add alternative Tel-to-
Feature).