Polycom MGC Administrator, Administrator'S Manual

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MGC Administrator’s Guide
7-9
Flow Using the Address Book”). The carrier conveys the dial-in number to
the gateway - 1721 in the example (step 2 in Figure 7-5).
Figure 7-5: Call Flow Using the Address Book
The Gateway finds the appropriate entry in the Address Book (step 3 in
Figure 7-5). If the Address Book contains the IP address of the destination
endpoint, the call will be routed to the appropriate endpoint directly (step 6 in
Figure 7-5). If the Address Book contains the alias of the endpoint for
example, 501 in E.164 format, the alias is sent to the gatekeeper for address
translation (step 4 in Figure 7-5). The gatekeeper returns the IP address of the
endpoint to the gateway (step 5 in Figure 7-5). The gateway then routes the
call to the appropriate endpoint.
In this method, each dial-in number is an entry in the speed dial table;
therefore, the gateway will require the use of many dial-in numbers. If the
conversion table includes the IP address of the endpoint, the gateway can
route the call without the presence of a gatekeeper. To use the endpoint's alias,
a gatekeeper must be present in the network. However there is no need to
change the configuration of any of the H.323 endpoints.
Forwarding Service
In the Forwarding Service method, the administrator allocates a few dial-in
numbers (from the range of dial-in numbers received from the carrier) to the
MCU/Gateway, for example, 1815 to 1825; therefore, there cannot be an
assignment between endpoints and dial-in numbers. Instead, the H.320