User`s manual

MP-1xx H.323 User’s Manual 8. Gateway Capabilities Description
Version 4.4 151 March 2005
8 Gateway Capabilities Description
8.1 Redundant Gatekeeper Implementation
The redundant Gatekeeper mechanism (IsRedundantGKUsed=1), similar to the Alternate
Gatekeeper procedure (described in para. 7.2.6 in the H.323 standard), provides MP-1xx
gateways with Gatekeeper redundancy options. This mechanism allows the gateway to use up to
two additional Gatekeepers as a backup in the event of a primary Gatekeeper failure.
The redundant Gatekeeper mechanism is identical to the Alternate Gatekeeper mechanism with
the exceptions that all Alternate Gatekeeper fields in RAS messages are ignored, and the IP
addresses of the two redundant Gatekeepers are provided by the user (via the Embedded Web
Server or the ini file) and not by the primary Gatekeeper.
When Gatekeeper redundancy is enabled, if there is no response from the primary Gatekeeper or
if a registration request is rejected by the Gatekeeper (RRJ), the gateway tries to communicate
with one of the two redundant Gatekeepers. When a redundant Gatekeeper is found, the gateway
registers with it and continue working with it until the next failure occurs (current Gatekeeper is
not responding). If none of the Gatekeepers respond, the gateway goes over the list again and
works with the first responsive Gatekeeper.
The MP-1xx gateway can fallback to the internal ‘Tel to IP Routing’ table when communication
with Gatekeepers is lost. If this option is enabled (IsFallbackUsed=1), the MP-1xx starts using its
internal routing table, and works without a Gatekeeper. The MP-1xx continues scanning for an
active Gatekeeper. When such Gatekeeper is found, the gateway switches from internal routing
back to Gatekeeper routing.
To enable redundant Gatekeepers set the following parameters in the ini file:
• IsGatekeeperUsed = 1
• IsRedundantGKUsed = 1
• GatekeeperIP = IP address of the primary Gatekeeper
• GatekeeperIP = IP address of the first redundant Gatekeeper
• GatekeeperIP = IP address of the second redundant Gatekeeper
Note: Users can use the Alternate Gatekeeper mechanism (AlternativeGKUsed)
described in para. 7.2.6 in the H.323 standard instead of the redundant
Gatekeeper mechanism. The Alternative and Redundant mechanisms
mustn’t be used simultaneously.