3Com 4500 PWR 26-Port Configuration Manual page 547

I n WRED algorithm, an upper limit and a low
a re processed as follows.
When the current queue length is sm
When the queue leng
When the queue length is betwe
are dropped at random. The long
dropped. However,
I n WRED, random numbers
p olicy is determined by IP preced
W RED prevents glob
s ession slowed down because
different rates in any case and the link bandwidth can be fully utilized.
Traffic mirroring
Traffic mirroring identifies traffic using ACLs and duplicates the matched packets to the destination
mirroring port or CPU depending on your configuration. For information abou
Mirroring module of this manua
QoS o C nfiguration
Complete the following tasks to configure QoS:
Configuring Priority Trust Mode
Configuring the Mapping between 802.1p
Priority and Local Pre
Setting the Priority of Protocol Packets
Marking Packet Priority
Configuring Traffic Policing
Configuring Line Rate
Configuring VLAN Mapping
Configuring Queue Scheduling
Configuring WRED
Configuring Traffic Mirroring
Configuring Priority
Refer to section
Configuration prerequisites
The priority trust mode to be adopted has been determined.
The port where priority trust mode is to be configured has been determined.
The port priority value has been determined.
th exceeds the upper limit
en the lower limit
er the queue, the
a maximum drop probability
are generated to dete
ence, packets with
al TCP session synchronization
of its packets being
l.
Task
cedence
Trust Mode
Priority Trust Mode for introduction to priority trust m
er limit a re set for ea ch queue, and the packets in a queue
aller than the lower l imit, no packet is dropped;
, all the ne wly received packets are dropped;
and the upper limit,
more likely the newly re
exists.
rmine the packets to be dropped. As the dropping
lower pre cedence are more likely to be dropped.
. It enable s other TCP sessions to be free of a TCP
dropped. I n this way, TCP sessions can operate in
Optional
Optional
Optional
Optional
Optional
Optional
Optional
Optional
Optional
Optional
45-13
the newly received packets
ceived packets may be
t port mirroring, refer to the
Remarks
ode.