TANDBERG Gatekeeper - Manual (Page 28)

TANDBERG Gatekeeper User Guide
Page 28 of 105
6. Unregistered Endpoints
Although most calls are made between endpoints registered with a Gatekeeper or Border Controller, it is
sometimes necessary to place a call to or from an unregistered endpoint.
6.1. Calling from an Unregistered Endpoint
An unregistered endpoint can call an endpoint registered with the Gatekeeper. If there are no firewalls
between the unregistered endpoint and the called endpoint, it is possible (though not recommended) to
place the call by dialing the target endpoint's IP address. A better way of placing the call from an
unregistered endpoint is to pass the alias of the called endpoint to the Gatekeeper. The Gatekeeper will
then resolve the alias and place the call as normal.
Not all endpoints allow you to enter an alias and an IP address to which the call should be placed. In that
case you can simply place the call to the IP address of the Gatekeeper, with no alias information. The
Gatekeeper may be configured to associate all such anonymous calls with a single destination alias. This
is achieved with the command:
xConfiguration Gatekeeper Unregistered Caller Fallback:
or using the web interface via Gatekeeper Configuration > Gatekeeper Configuration and entering the
alias in the Fallback alias for unregistered caller destination field.
6.2. Calling to an Unregistered Endpoint
Calls can be placed to an unregistered endpoint by dialing its IP address or (if the DNS system has been
appropriately configured) using an H.323 URI.
If URI dialing is used, DNS is queried for a call signaling address and, if found, the call is placed to that
address. See URI Dialing (section 9) for details of how to configure the Call Signaling SRV Record.
It is sometimes undesirable for a system to place a call to an IP address directly. Instead, you may want
a neighbor to place the call on behalf of the Gatekeeper. You can configure this on the Gatekeeper using
the command:
xConfiguration Gatekeeper CallsToUnknownIPAddresses:
or using the web interface via Gatekeeper Configuration > Gatekeeper and from within the Configuration
section selecting the desired option from the Calls to unknown IP addresses drop-down menu.
There are three possible settings:
Direct
This setting will allow the endpoint to make the call to the unknown IP address without querying any
neighbors. The call setup would occur just as it would if the far end were registered directly to the local
system.
Indirect
Upon receiving the call the Gatekeeper will check to see if the address belongs to one of its local
subzones. If so, it will allow the call. If not, it will query its neighbors for the remote address, relying on
the response from the neighbor to allow the ability for the call to be completed; connecting through the
routing rules as it would through the neighbor relationship.
Off
This will not allow any endpoint registered directly to the Gatekeeper to call an IP address of any system
not also registered directly to that Gatekeeper.
The default is
Indirect
.