AudioCodes Mediant 800 MSBG - Configuring SAS Redundant Mode

SIP User's Manual 594 Document #: LTRT-12804
Mediant 800 MSBG
8.5.3.3 Configuring SAS Redundant Mode
This section describes how to configure the SAS redundant mode. These settings are in
addition to the ones described in ''Configuring Common SAS Parameters'' on page 591.
Note: The VoIP CPEs (such as IP phones or residential gateways) need to be
defined so that their primary proxy is the external proxy, and their redundant
proxy destination addresses and port is the same as that configured for the
device's SAS IP address and SAS SIP port.
¾ To configure SAS redundant mode:
1. Open the 'SAS Configuration' page (Configuration tab > VoIP menu > SAS > Stand
Alone Survivability).
2. From the 'SAS Survivability Mode' drop-down list, select one of the following,
depending on whether the UAs support homing (i.e., they always attempt to operate
with the primary proxy, and if using the redundant proxy, they switch back to the
primary proxy whenever it's available):
• UAs support homing: Select 'Always Emergency'. This is because SAS does
not need to communicate with the primary proxy of the UAs; SAS serves only as
the redundant proxy of the UAs. When the UAs detect that their primary proxy is
available, they automatically resume communication with it instead of with SAS.
• UAs do not support homing: Select 'Ignore REGISTER'. SAS uses the keep-
alive mechanism to detect availability of the primary proxy (defined by the SAS
Proxy Set). If the connection with the primary proxy resumes, SAS ignores the
messages received from the UAs, forcing them to send their messages directly to
the primary proxy.
3. Click Submit.
8.5.3.4 Configuring Gateway Application with SAS
If you want to run both the Gateway and SAS applications on the device, the configuration
described in this section is required. The configuration steps depend on whether the
Gateway application is operating with SAS in outbound mode or SAS in redundant mode.
Note: The Gateway application must use the same SAS operation mode as the SIP
UAs. For example, if the UAs use the SAS application as a redundant proxy
(i.e., SAS redundancy mode), then the Gateway application must do the
same.