Chapter 31: Load Balancing
STANDARD Revision 1.0
C4® CMTS Release 8.3 User Guide
© 2016 ARRIS Enterprises LLC. All Rights Reserved.
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converted to a count for both the DS and US. This is done by multiplying the rule threshold (as a percentage) with the DS
load of the heaviest loaded channel pair, and by multiplying the rule threshold (as a percentage) with the US load of the
heaviest loaded channel pair.
For example, if the heaviest loaded channel pair has 50 modems on the DS and 40 modems on the US, for a rule threshold
of 10%, the count threshold is 5 for the DS and 4 for the US. In this case, load balancing would continue to occur when the
difference in load between the heaviest loaded channel pair and the lightest channel pair was greater than 5 for the DS or
greater than 4 for the US.
The start thresholds, downstream-start-threshold and upstream-start-threshold, determine when load balancing is
allowed to begin. These are global settings and apply only when the method associated with a load balance group is set to
utilization. They are used to prevent the load balancing feature from moving CMs when channels are lightly loaded. An
MSO can use start thresholds to define when channel loading is great enough to begin moving modems from highly-loaded
channels to lightly-loaded channels where the rule threshold has also been exceeded. If no channels in the load balance
group exceed either of the start thresholds, the load balancer does not attempt to balance the channels. By default, the
minimum start thresholds are set to 1%, which means they have will have no effect unless explicitly configured to be a
higher value.
Note: If either the downstream-start-threshold or the upstream-start-threshold has been exceeded, load balancing will
occur for a load balance group where its associated rule threshold has also been exceeded.
For example, an MSO might set both start thresholds to a value of 30%, based on the reasoning that if all the channels in a
load balance group are under 30% loaded, it is not necessary for the channels to be in balance. But if the load on any of the
channels exceeds 30% and the associated rule threshold has also been exceeded, modems will be moved in that load
balance group.
Default Configuration
If no load balancing configuration commands are entered, by default, load balancing would be configured as follows (and
shown in the example output below).
A general group default policy (0) is created.
