AudioCodes MP-26 series, User Manual

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User's Manual 9. Configuring VoIP Parameters
Version 4.4.0 95 MP26x/MP27x
9.1.1 Configuring Proxy Redundancy
The Redundant Proxy feature allows the configuration of a backup SIP proxy server to
increase Quality of Service (QoS). Once this feature is enabled, the device identifies cases
where the primary proxy does not respond to SIP signaling messages. In these cases, the
device registers to the redundant proxy and seamlessly continues normal functionality,
without any noticeable connectivity failure or malfunction with the primary proxy.
The Redundant Proxy feature includes two operational modes:

Asymmetric mode: This mode assigns the primary proxy a higher priority for
registration over the redundant proxy. Once the device is registered to the primary
proxy, it sends keep-alive messages (using SIP OPTIONS messages) to the primary
proxy. If the primary proxy does not respond, the device registers to the redundant
proxy, but continues sending keep-alive messages to the primary proxy. If the primary
proxy responds to these keep-alive messages, the device re-registers to the primary
proxy.

Symmetric mode: In this mode, both proxies are assigned the same priority for
registration. Once the device is registered to a proxy (primary or redundant), it sends
keep-alive messages to this proxy. The device switches proxies only once the proxy to
which it has registered, does not respond.
In both modes, the following applies:

If the device is not registered (i.e., if the proxy server - redundant or primary - to which
the device currently tries to register does not respond), the device attempts to register
to an alternative proxy. These attempts continue until the device successfully
registers.

If this feature is enabled and you reboot the device, it registers to the last proxy to
which it was trying to register (not necessarily to the primary proxy).

To configure proxy redundancy:
1. From the menu bar, click the Voice Over IP menu; the Signaling Protocol tab screen
appears.
2. Define a primary proxy server (under the SIP Proxy and Registrar group):
a. Select the ‘Use SIP Proxy’ check box.
b. In the 'Host Name or Address' field, enter the primary proxy's IP address.
c. In the 'Proxy Port' field, enter the primary proxy's port number.
3. Define a redundancy proxy server (under the SIP Proxy and Registrar group):
a. Select one of the following check boxes: 'Use SIP Registrar' or 'Use SIP Proxy IP
and Port for Registration'.
a. Select the 'Use Redundant Proxy' check box.
b. In the 'Redundant Proxy Address' field, enter the redundant proxy's IP address or
DNS name.
c. In the 'Redundant Proxy Port' field, enter the redundant proxy's port number.