Miscellaneous

DOCSIS concatenation combines multiple upstream packets into one packet to reduce packet overhead and overall latency, and to increase transmission efficiency. Using concatenation, a DOCSIS modem needs to make only one bandwidth request for a concatenated packet, as opposed to making a different bandwidth request for each individual packet; this technique is especially effective for bursty real-time voice traffic.

The following information is entered by the user to enable concatenation, determine the HMAC-MD5 algorithm specification (RFC 2104 or RFC 1321) to be used, and specify the authentication string used between the provisioning server and the CMTS.

Modem Capability---Concatenation Support

Specifies whether the modem supports concatenation of upstream packet requests:

Use RFC 2104 HMAC-MD5

This mandatory field specifies the algorithm used to compute the CMTS Message Integrity Check (MIC). If yes, the HMAC-MD5 algorithm specified in RFC 2104 is used; if no, the algorithm specified by RFC 1321 is used. (The algorithm used must match the one used on the CMTS.)

CMTS Authentication

Specifies an authentication string to be used between the provisioning server (which creates the configuration files) and the CMTS. It allows the CMTS to authenticate the modem provisioning with a central authentication service, such as a RADIUS server. This field is typically used only for one-way modems that use telco-return.

Example: [blank]---This is the default value. Cisco recommends that you leave this field empty.

Note: If the CMTS Authentication setting on the line card does not match the CMTS Authentication setting in the DOCSIS configuration file, the modem will connect to the CMTS in state "reject m" and will resave no bandwidth. This could be used for non-paying customers.

Related Topics

Overview: Cisco DOCSIS CPE Configurator