Polycom MGC Administrator, Administrator'S Manual

Page: 424 / 584

Chapter 7 - Configuring the Gateway
7-16
Address Book IP-to-IP
In the Address Book method, the gateway includes a conversion table in
which each E.164 ID number is assigned a destination alias or IP address. In
this method, the destination endpoint details are taken from the Address Book
table. It is used when an internal IP endpoint calls an external IP address
through a firewall.
Figure 7-10: IP-to-IP System Configuration Using Address Book
For example, when the H.323 endpoint dials 8342#33 (step 1 in Figure 7-11,
“IP-to-IP Call Flow Using Address Book”), the number is sent to the
gatekeeper A where the digits 83 are identified as the gateway prefix (step 2
in Figure 7-11). Gatekeeper A translates the prefix to the IP address of the
gateway (step 3 in Figure 7-11) and sends this address to the endpoint. The
call is transferred to the gateway with the digits 42#33 (step 4 in Figure 7-11).