TANDBERG Gatekeeper - Manual (Page 23)

TANDBERG Gatekeeper User Guide
Page 23 of 105
4.7. Alternates
Alternate Gatekeeper support is provided to increase the reliability of your deployment. If one
Gatekeeper becomes unavailable, perhaps due to a network or power outage, another will be used as an
Alternate. Alternates share responsibility for their endpoint community: an individual endpoint may be
registered with any one of the Alternates. You should configure Alternates identically for all registration
and call features such as authentication, bandwidth control and policy. If you do not do this, endpoint
behavior will vary unpredictably depending on which Alternate it is currently registered with. Alternates
should also be deployed on the same LAN as each other so that they may be configured with the same
routing information such as local domain names and local domain subnet masks.
Each Gatekeeper may be configured with the IP addresses of up to five Alternates. When an endpoint
registers with the Gatekeeper, it is presented with the IP addresses of all the Alternates. If the endpoint
loses contact with its initial Gatekeeper, it will seek to register with one of the Alternates. This may result
in your endpoint community's registrations being spread over all the Alternates.
When a Gatekeeper receives a Location Request, if it cannot respond from its own registration
database, it will query all of its Alternates before responding. This allows the pool of registrations to be
treated as if they were registered with a single Gatekeeper.
The Alternate Gatekeepers can be configured within the web interface via
Gatekeeper Configuration >
Gatekeeper within the Alternate Gatekeepers section (see Figure 5).
Figure 5: Alternate Gatekeeper configuration