User's Manual Part 1

4: IP Network Planning
APCD-LM043-8.0 (DRAFT C) 61
an IP subnet that allows 512 addresses (510 usable, since host address 0 and all 1s are
reserved for IP broadcast) can be used. This is a subnet with a 23-bit netmask, allowing the
last 9 bits of the IP address to be used for host addresses. If more than 510 IP addresses are
needed at a later stage, then every EUM and subscriber needs to have a new IP subnet mask
assigned.
Routed mode does not allow the assignment of subscribers to different IP subnets in the radio
network. Also, you cannot assign subscribers to one IP subnet and EUMs to another IP
subnet.
Network Address Translation (NAT) can be used to provide private-to-public IP address-
mapping for subscribers. Note that not all user applications work through NAT. NAT must be
provided by a third-party device, often the gateway router, and is beyond the scope of this
document.
NOTE: PPPoE is not supported in Routed mode.