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Cisco uBR10012 Universal Broadband Router Software Configuration Guide
OL-1520-05
Chapter4 Managing Cable Modems on the Hybrid Fiber-Coaxial Network
Configuring the Dynamic Map Advance Algorithm
Tip System defaults are to have dynamic ranging interval enabled, dynamic ranging backoff enabled, and
fixed data backoffs for each upstream of a cable interface.
The default automatic insertion interval setting enables the Cisco automatic initial ranging period
algorithm, where lower and upper default values of 50 msecs and 2 secs are used. The default
automaticrange-backoff setting enables the dynamic backoff algorithm.
Configuring the Dynamic Map Advance Algorithm
A CMTS administrator can enhance the upstream throughput from a CM connected to the
CiscouBR10000series CMTS. The system employs a new algorithm that automatically tunes the
lookahead time in MAPs, based on several input parameters for the corresponding upstream channel.
The use of dynamic and optimal lookahead time in MAPs significantly improves the per-modem
upstream throughput.
Caution Only a trained CMTS administrator should adjust these values.
Command Purpose
[no] cable
insertion-interval
[automatic [Imin [Imax]]] |
[msecs]
cable insertion-interval
automatic min 25-2000
cable insertion-interval
max 500-2000
no cable insertion-interval
cable insertion-interval
100-2000
Enables or disables the dynamic ranging interval algorithm. If lower
and upper bounds for varying the period are not specified, the
system uses default frequency values of initial ranging upstream
slots between 50 milliseconds to 2 seconds, respectively.
Sets the lower bound on the initial ranging period for the automatic
ranging algorithm.
Sets the upper bound on initial ranging period for the automatic
ranging algorithm.
Resets fixed initial ranging period to default value of 500 msecs.
Also invokes fixed initial ranging algorithm.
Enables fixed initial ranging period algorithm with specified fixed
period (msecs).