User's Manual Part 1

4: IP Network Planning
APCD-LM043-8.0 (DRAFT C) 69
4.7 IP Plan Process
This section provides a set of questions and responses that will assist you with the IP planning
process.
4.7.1 Which CCU protocol mode is recommended for use?
Switched Ethernet Mode
• Small network with one CCU and up to 300 subscribers per router.
• Network with multiple CCUs in broadcast domain, where no CCU Ethernet port sees
more than 256 Ethernet devices. (v4.0 restriction)
• Network with multiple CCUs in broadcast domain, with a total of no more than 650
Ethernet devices.
For networks larger than those above, the broadcast domain must be restricted using
additional routers (not CCU), multi-port router(s), and/or VLANs.
To reserve public IP addresses for subscribers only, the EUMs can be assigned to a private IP
subnet for management purposes. This provides some added security against external
attacks. The subscribers can be assigned the public IP addresses using DHCP if desired.
To allow different IP subnets for different subscribers. The subscribers can be assigned private
or public IP addresses as desired, using DHCP if desired.
IP Subnetting All radio network devices, including
the CCU radio interface, EUMs, and
subscribers are on one IP subnet.
An arbitrary number of IP subnets
can be supported as configured in
the gateway router.
Number of routes in
gateway router
One per radio network One per IP subnet defined.
Radio Network
Protocols allowed
IP, ARP/RARP IP, ARP/RARP, PPPoE
Prevention of
Broadcast Attacks
(SMURF or other
denial of service
attack)
Add routes to CCU to prevent IP
broadcasts from passing between
CCU Ethernet and radio networks.
Damage is limited to single radio
network.
Recommend blocking broadcasts at
the gateway router as well.
Must be handled by gateway router.
Attacks are limited to Ethernet
broadcast domain, which can be
several radio networks.
Routed Mode
Switched Ethernet and
Through Only Modes