Specifications

DOCSIS 1.1 for Cisco uBR905 and Cisco uBR925 Cable Access Routers and Cisco CVA122 Cable Voice Adapters

Information About DOCSIS 1.1 Support

Cisco IOS Release 12.2(15)CZ

Benefits

DOCSIS 1.1 includes a rich set of features that provide advanced and flexible QoS capabilities for

various types of traffic (voice, data, and video) over the cable network. It also provides enhanced security

and authentication features.

Baseline Privacy Interface Plus Enhancement

The Plus (+) version of the Baseline Privacy Interface (BPI+) in DOCSIS 1.1 provides a set of extended

services within the MAC sublayer that increase performance and system security. Digital certificates

provide secure authentication for each cable modem, to prevent identity theft on the basis of MAC and

IP addresses. Advanced encryption provides a secure channel between the cable modem and the CMTS,

and secure software download allows a service provider to upgrade the software on cable modems,

without the threat of interception, interference, or alteration of the software code.

Dynamic Service Flows

The dynamic creation, modification, and deletion of service flows allows for on-demand reservation on

Layer 2 bandwidth resources. The CMTS can now provide special dynamic QoS (DQos) to the cable

modem dynamically for the duration of a voice call or video session, as opposed to the static

provisioning and reservation of resources at the time of cable modem registration. This provides a more

efficient use of the available bandwidth.

Concatenation

The cable modem concatenates multiple upstream packets into one larger MAC data frame, allowing the

cable modem to make only one time-slot request for the entire concatenated MAC frame, as opposed to

requesting a time slot for each individual packet. This reduces the delay in transferring the packet burst

upstream.

For this configuration... The result is...

DOCSIS 1.1 cable modems with DOCSIS 1.0 CMTS

Cable modems receive DOCSIS 1.0 features and

capabilities. BPI is supported if it is available and

enabled on the CMTS.

DOCSIS 1.1 cable modems with DOCSIS 1.0+ CMTS

Cable modems receive basic DOCSIS 1.0 support.

BPI is supported if it is available and enabled on the

CMTS. In addition, cable modems also receive the

following DOCSIS 1.1 features:

• Multiple SIDs per cable modem

• Dynamic Service MAC messaging initiated by

the cable modem

• Unsolicited grant service (UGS,

CBR-scheduling) on the upstream

• Separate downstream rates for any given cable

modem, based on the IP-precedence value

• Concatenation

DOCSIS 1.1 cable modems with DOCSIS 1.1 CMTS

Cable modems receive all the DOCSIS 1.1 features

listed in this document. BPI+ is supported if it is

available and enabled on the CMTS.