Cisco DNCS System Release 2.7 3.7 4.2 Guia Do Desenho
2-2
Guidelines for Configuring the DBDS for DOCSIS
4000358 Rev B
Assumptions
Introduction
This section lists the assumptions that Cisco has made about your system so that we
can provide these guidelines for provisioning DOCSIS onto the DBDS.
The IP addresses used in this document are only examples. Cable service providers
The IP addresses used in this document are only examples. Cable service providers
should determine their own IP addressing scheme. The IP subnet mask(s) that the
cable service provider chooses determines the number of end-user devices that can
be connected per CMTS DOCSIS MAC domain. Therefore the cable service
provider’s IP address blocks might be different from those used in these guidelines.
What Did We Assume?
We have made the following assumptions about your system:
•
•
DBDS network elements use the 172 network (172.16.0.0 – 172.31.255.255) and the
192 network (192.168.0.0 – 192.168.255.255).
•
The entire 10 network is dedicated to end-user devices.
•
The cable service provider will not use any subnets from the private 10 network IP
addresses that are currently being used by existing DHCTs
and DBDS network
elements
in order to avoid any IP address conflict.
•
The cable service providers will assign one subnet block to the integrated cable
modem and another subnet block to the stand-alone cable modem.
Note: Although stand-alone cable modems and integrated cable modems could
share the same subnet block, Cisco recommends that they use a different subnet
block for security purposes.
•
This chapter assumes that each CMTS DOCSIS MAC domain can support a
maximum of 2000 stand-alone cable modems or integrated cable modems. (The
DOCSIS SID number places an absolute limit of 8191 cable modems per DOCSIS
MAC domain).
•
The cable service provider does not track the PC connected behind the cable
modem. Therefore, an unsubscribed PC category is not required.
•
The DHCP servers must implement the specifications in Dynamic Host Control
Protocol, RFC-2131, March 1997.
•
Interface bundling, which allows multiple cable interfaces to share a single IP
subnet
•
The cable service provider does not allow for self-provisioning of integrated cable
modems. MAC addresses for integrated cable modems are pre-provisioned in a
database. Therefore, an unregistered integrated cable modem category is not
required.
, is not enabled on the CMTS.
•
The cable service provider does allow self-provisioning for stand-alone cable
modems, and no cable modem MAC address is pre-provisioned in the database.
Therefore, an unregistered stand-alone cable modem category is required. In the
self-provisioning model, the subscriber buys his or her own cable modem,
connects to the cable service provider’s network, and uses the cable service
provider’s user interface to provide all of the required information.