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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Note that a given modem can have both DCC and DBC failed-list entries.
For DCC failures: modems may appear in the DCC load balance failed list multiple times, once for each source and
destination DS/US channel pair when the failure occurred. The load balancing software will consider a DS/US channel pair
as a valid target for a given modem unless that modem has failed to move to that channel pair the exclude-count number
of times. Until the modem has failed the exclude-count number of times for every destination DS/US channel-pair in the
associated fiber-node, the modem will still be considered a candidate for a DCC move.
For DBC failures: modems may appear in the DBC load balance failed list only once, but an occurrence contains separate
entries for failures to move to a downstream and an upstream channel-set. The load balancing software will consider any
DS or US channel-set as a valid target for a given modem unless that modem has failed to move to that channel set the
exclude-count number of times. Until the modem has failed the exclude-count number of times for a given direction (DS or
US), the modem will still be considered a candidate for a DBC move.
For both DCC and DBC failures: the timestamp indicates the time of the last failed attempt.
By default a modem will only be allowed to fail being moved to a given destination a single time. It has been observed that
load balancing is more effective when the default value of 1 is changed to a value like 3. This prevents the failed-list from
getting excessively large, which limits the number of modems that are available and may negatively impact the
effectiveness of the load balancing software. The following CLI can be used to change the exclude count:
configure cable load-balance failed-list exclude-count x
The failed list by default only shows the modems that have reached the exclude-count limit for any given destination. To
see all failures to destinations that have not yet reached the exclude-count limit, use the verbose option:
show cable load-balance failed-list verbose
Modems on the failed-to-load-balance list will be aged out when the timeout value is non-zero. The following command is
used to set this interval:
configure cable load-balance failed-list timeout x
Where: x is the number of hours that a failed modem stays on the list. The minimum setting is one hour. The default value
is 0 which means that the modems will never be removed from either list unless it is manually cleared. It is
recommended that this value be set to a value such as 48 to allow for transient DCC or DBC issues caused by things
such as cable cuts, etc.
