This is the index identifying a specific DHCP address pool among up to 20 that this device, per the description specifically the Avaya G250/G350 gateway platforms, can host when acting as a DHCP server, letting an admin manage several distinct address scopes, for example separate pools for different VLANs or departments, as independent rows in this table. An admin adding a 21st pool would find the operation rejected, since the description specifies this platform's hard limit of 20 pools. For example, pool index 3 might represent the address range handed out to a guest VLAN, entirely separate from pool index 1 serving the main office VLAN.