Nortel 1000 Description, Installation And Operation Manual page 33

Figure 3
Gatekeeper-routed call
Gatekeeper-routed calls
In Gatekeeper-routed calls, the Gatekeeper returns the Gatekeeper's IP
address and port as both the destination for the originating call and the
originator for the destination, rather than the end-point address and port.
Figure 3 represents a Gatekeeper-routed call. The destination IP address
provided by the Gatekeeper is the Gatekeeper's IP address. All messages are
routed through the Gatekeeper.
Overview of IP Trunk 3.01
IP Trunk Description, Installation, and Operation
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