EtherHaul Operation, Administration and Maintenance Manual
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set eth <eth> [pfc-mode <value>]
<eth> : host | eth0 | eth1 | eth2 | eth3 | eth4
<pfc-mode value> :rf | disable
set pfc <pfc-id-list> [min-threshold <0..100>] [max-threshold
<0..100>]
<pfc-id-list> : list: | integer 1..32
set egress-qos eth0 <cos-id-list> pfc <pfc-id-list>
9.8.5
Queue Management
The EtherHaul allows controlling the drop mode by setting it to one of the following
options:
Simple – set queue length in microseconds
Length – set queue length us Kbytes
WRED
The default queue mode and length is Simple with queue length of 2000 microseconds.
set egress-qos <eth> <cos-id-list> [drop-mode <value>]
<eth> : host | eth0 | eth1 | eth2 | eth3 | eth4
<cos-id-list> : list: | integer 0..7
<drop-mode {simple <queue-length-microsec 1.. 1000000>} |
{length <queue-length-in-kbytes 10..10000> } |{wred <wred-id>}
9.8.6
Weighted Random Early Detection (WRED)
Queues have several different queue thresholds, each queue threshold is associated to
a particular traffic class.
Weighted random early detection (WRED) is a queue management algorithm with
congestion avoidance capabilities. It is an extension of Random Early Detection (RED) in
which a single queue may have several different queue thresholds. Each queue
threshold is associated to a particular traffic class; a queue may have lower thresholds
for lower priority packet.
A queue buildup will cause the lower priority packets to be dropped, hence protecting
the higher priority packets in the same queue. In this way quality of service
prioritization is made possible for important packets from a pool of packets using the
same buffer a standard traffic will be dropped instead of higher prioritized traffic.
WRED is very useful in improving TCP performance.