| Description | This table contains the attributes of the QoS enforce rules
present on the CMTS.
These enforce rules define the criteria for identifying
subscribers who over consume resources. This could be as
simple as bytes transmitted over the last monitoring
duration and checked at a rate equal to the sample rate.
In the sliding window concept used, the monitoring duration
is the size of the window. This window slides by an amount
that is equal to the sample rate. At every sample rate the
bytes transmitted in the time equal to a monitoring duration
is checked. If this is found to be larger than the threshold
limit which is calculated by multiplying the defined average
rate by the monitoring duration per monitoring duration,
the subscriber is flagged as over consuming. Else the
monitoring will continue.
For example let the monitoring duration be 360 minutes and
sample rate be 30 minutes. If the average rate is 2kbits/sec
then every 30 minutes we check if the bytes transmitted in
the last 360 minutes exceeded 5.4Mbytes bytes. If so, the
subscriber is over consuming.
The enforce rule has a one to one mapping to QoS profiles
in case of DOCSIS1.0 (and DOCSIS1.0+ modems) and to
service class names in case of DOCSIS1.1 and
DOCSIS2.0 modems.
It defines the registered QoS parameter set and an enforced
QoS parameter set be applied if found to be violating the
registered QoS parameter set.
The enforce rule also defines a penalty period for which
the enforced QoS parameter set will be applied. The
registered QoS parameter set will be restored when the
penalty period expires.
The monitoring can be of two types:
1) Legacy/Basic monitoring: There is only one threshold and
one monitoring-duration and the monitoring-duration
can be more than one day and within a day there is no
distinction among hours as peak or offpeak hours. An
example would be:
monitoring duration : 2 days
Average rate : 2kbits/sec
2) Peak-offPeak monitoring: A maximum of two peak durations
can be defined with in a day and the remaining hours are
treated as off-peak and the monitoring will happen during
these offpeak hours if the offpeak duration and threhold
are defined. The monitoring-duration and threshold for
all three, first peak, second peak and offpeak can be
different. Here, the monitoring duration for any of the
peaks or offpeak cannot be more than a day. An
example when both peaks and offpeak are defined is:
First peak:
monitoring duration: Between 6am to 9am i.e., 3hours
Average rate : 2kbits/sec
Second peak:
monitoring duration: Between 6pm to 10pm i.e., 4hrs
Average rate : 3kbits/sec
Off peak:
Remaining hours in the day i.e.,
12 midnight to 6:00am,
9am to 6pm and 10pm to 12mignight.
monitoring duration: 2 hours
Average rate : 1kbits/sec. |