Cisco DNCS System Release 2.2 3.2 디자인 가이드
2-4
Guidelines for Configuring the DBDS for DOCSIS
4000358 Rev B
IP Address Assignment,
Continued
To use such a plan and to allow for network and subscriber growth within a region,
we recommend that you partition the 10 network into four different large subnets
with a 10-bit subnet mask (also known as the /10 prefix) as shown in the following
examples:
•
•
Subnet 1: 10.0.0.0 – 10.63.255.255
•
Subnet 2: 10.64.0.0 - 10.127.255.255
•
Subnet 3: 10.128.0.0 – 10.191.255.255
•
Subnet 4: 10.192.0.0 – 10.255.255.255
Note: The 10-bit subnet mask is equivalent to 255.192.0.0 net mask.
Subnet 1 (10.0.0.0/10) can be further subdivided into two subnets each with a /11
Subnet 1 (10.0.0.0/10) can be further subdivided into two subnets each with a /11
prefix to support integrated cable modems and DHCT CPEs:
•
•
10.0.0.0/11
•
10.32.0.0/11
Assuming that each CMTS DOCSIS MAC domain can support a maximum of 2000
integrated cable modems, you can partition the first subnet 10.0.0.0 /11 even further
to provide 1024 subnets with a /21 prefix. Assuming four blades or RF interfaces per
CMTS, this configuration can support 256 CMTS’s (1024 divided by 4). If each CMTS
DOCSIS MAC domain is assigned a subnet with a /21 prefix, this subnet can
support 2046 cable modems per CMTS DOCSIS MAC domain and can support 2046
IP addresses.
Note: The equivalent mask for the /11 prefix is 255.224.0.0. The equivalent mask for
Note: The equivalent mask for the /11 prefix is 255.224.0.0. The equivalent mask for
the /21 prefix is 255.255.248.0.
The first subnet 10.0.0.0/11 can be partitioned into 1024 subnets with /21 prefix and
The first subnet 10.0.0.0/11 can be partitioned into 1024 subnets with /21 prefix and
can be assigned to the registered integrated cable modems. The second subnet
10.32.0.0/11 can be partitioned into 1024 subnets with /21 prefix and can be
allocated to the DHCT CPE.
The following diagram provides an example of how you can partition Subnet 1
The following diagram provides an example of how you can partition Subnet 1
(10.0.0.0/10) to support integrated cable modems and DHCT CPEs: