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
5
Cisco IOS Release 12.2(15)CZ
Information About DOCSIS 1.1 Support
DOCSIS 1.1 is the first major revision of the initial DOCSIS 1.0 standard for cable networks. Although
the initial standard provided quality data traffic over the coaxial cable network, the demands of real-time
traffic such as voice and video required many changes to the DOCSIS specification. DOCSIS 1.1 also
includes support for the Baseline Privacy Interface Plus (BPI+) features, which improves and enhances
the DOCSIS 1.0 BPI security and authorization mechanisms.
Note At the time of publication, the DOCSIS 1.1 and BPI+ specifications are still being finalized. See the
CableLabs specifications web site (http://www.cablemodem.com/specifications.html) for the current
status on these specifications.
The following sections describe the DOCSIS 1.1 features in more detail:
• DOCSIS 1.1 Overview, page 5
• Baseline Privacy Interface Plus, page 7
• DOCSIS 1.1 Quality-of-Service, page 10
• Quality-of-Service Comparison, page 14
• SNMPv3 Support, page 15
• Additional DOCSIS 1.1 Features in Cisco IOS Release 12.2(15)CZ, page 16
• Migrating from Earlier Versions of DOCSIS, page 17
DOCSIS 1.1 Overview
The DOCSIS 1.1 specification provides the following functional enhancements over DOCSIS 1.0
coaxial cable networks:
• Enhanced quality-of-service (QoS) to give priority for real-time traffic such as voice and video:
– The DOCSIS 1.0 QoS model (a service ID [SID] associated with a QoS profile) has been
replaced with a service flow model that allows greater flexibility in assigning QoS parameters
to different types of traffic and in responding to changing bandwidth conditions.
– Support for multiple service flows per cable modem allows a single cable modem to support a
combination of data, voice, and video traffic.
– Greater granularity in QoS per cable modem in either direction, using unidirectional service
flows.
– Dynamic MAC messages create, modify, and delete traffic service flows to support on demand
traffic requests. The CMTS can also dynamically change the upstream and downstream
channels that the cable modem is using to proactively deal with potential congestion or noise
problems.
• Supported QoS models for the upstream are:
– Best-effort—Data traffic sent on a nonguaranteed best-effort basis.
– Committed information rate (CIR)—Guaranteed minimum bandwidth for data traffic.
– Real-time polling (RTPS)—Real-time service flows, such as video, that produce unicast,
variable-size packets at fixed intervals.