Specifications

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

How to Configure DOCSIS 1.1 Support

Cisco IOS Release 12.2(15)CZ

These procedures assume that you are using the Cisco DOCSIS Configurator Tool, version 3.6 or later,

to generate the DOCSIS 1.1 configuration files for the cable modems. This tool is available on Cisco.com

at http://www.cisco.com/cgi-bin/tablebuild.pl/cpe-conf.

DOCSIS 1.1 Feature Configuration

A DOCSIS 1.1-capable cable modem informs the CMTS that it is capable of DOCSIS 1.1 operation by

sending a DHCP request that includes option 60, Vendor Class Identifier, with a value of

“docsis1.1:xxxxxxx”, where xxxxxxx is an ASCII string with the hexadecimal encoding of the encoding

of the modem’s capabilities. This field informs the CMTS of the following information:

• DOCSIS version

• Concatenation support

• Fragmentation support

• Payload header suppression (PHS) support

• DOCSIS-compliant IGMP support

• BPI or BPI+ support

• Number of downstream SAIDs supported

• Number of upstream SAIDs supported

• Packet filtering support

• Dynamic Channel Change (DCC) support

The option 60 message does not enable DOCSIS 1.1 operation but only informs the CMTS of the cable

modem’s capabilities. To enable the different DOCSIS 1.1 features, you must specifically enable the

following options in the DOCSIS configuration file:

• Baseline privacy configuration setting

• Privacy enable configuration setting

• Payload header suppression

• Downstream service flow encodings

• Upstream service flow encodings

• Maximum number of classifiers

Note For more information about these parameters, see Appendix D, “CM Configuration Interface

Specification,” in the DOCSIS 1.1 specification, Data-Over-Cable Service Interface Specifications

Radio Frequency Interface Specification (SP-RFIv1.1-I08-020301).