3Com V7111 - VCX 4 Channels Analog FXO Media Gateway User Manual page 158

Add Reserved Clients
Figure 66
Enter the IP address you want to provide to the 3Com Gateway.
3
The IP address reservation should be inside your DHCP Scope.
4
Enter the hardware MAC address, 12 digits, from your 3Com Gateway.
5
Enter Client name; it can be any free text.
6
Select Add and then Close.
7
From Scope menu in the main screen, select Active Leases.
8
158 3Com VCX V7111 VoIP SIP Gateways User Manual