tswtclmt(7ipp) IP Quality of Service Modules tswtclmt(7ipp)
NAME
tswtclmt - Time Sliding Window Three Conformance Level Meter
DESCRIPTION
The Time Sliding Window Three Conformance level meter (tswtcl) meters a traffic stream and determines the conformance level of its packets.
Packets are deemed to belong to one of the three levels, Red, Yellow or Green, depending on the committed and peak rate.
The meter provides an estimate of the running average bandwidth. It takes into account burstiness and smoothes out its estimate to approx-
imate the longer-term measured sending rate of the traffic stream.
The estimated bandwidth approximates the running average bandwidth of the traffic stream over a specific window (time interval). tswtcl
estimates the average bandwidth using a time-based estimator. When a packet arrives for a class, tswtcl re-computes the average rate by
using the rate in the last window (time interval) and the size of the arriving packet. The window is then slid to start at the current time
(the packet arrival time). If the computed rate is less than the committed configuration parameter, the packet is deemed Green; else if the
rate is less than the peak rate, it is Yellow; else Red. To avoid dropping multiple packets within a TCP window, tswtcl probabilistically
assigns one of the three conformance level to the packet.
STATISTICS
The tswtcl module exports global and per-class statistics through kstat:
Global statistics:
module: tswtclmt instance: <action id>
name: tswtclmt statistics class <action name>
green_bits <number of bit in green>
green_packets <number of packets in green>
red_bits <number of bits in red>
red_packets <number of packets in red>
yellow_bits <number of bits in yellow>
yellow_packets <number of packets in yellow>
FILES
/kernel/ipp/sparcv9/tswtclmt
64-bit module (SPARC only.)
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWqos |
+-----------------------------+-----------------------------+
SEE ALSO
ipqosconf(1M), dlcosmk(7IPP), dscpmk(7IPP), flowacct(7IPP), ipqos(7IPP), ipgpc(7IPP), tokenmt(7IPP)
RFC 2859, A Time Sliding Window Three Colour Marker (TSWTCM) W. Fang, N. Seddigh, B. Nandy -- The Internet Society, 2000
SunOS 5.10 29 Sep 2004 tswtclmt(7ipp)
