Addendum

separating the starting and ending queue numbers with a
hyphen
backplane Specify that the ECN marking configured for each queue
applies to backplane ports
Default By default, ECN marking is disabled on all queues.
Command
Modes
CONFIGURATION mode
Command
History
Version 9.3.0.0 Introduced on the Z9000 platform
Usage
Information
You can add or remove ECN marking configuration on a list of queues on all
backplane ports. All of the configured attributes apply to all the backplane ports
and are for each queue. You can configure all the data queues. For Z9000, you can
configure queues 0-3. For S6000, you can configure queues 0-7. By default, ECN
marking is disabled on all queues. When you enable wred-ecn, and the number of
packets in the queue is below the minimum threshold, packets are transmitted per
the usual WRED treatment. When you enable wred-ecn, and the number of
packets in the queue is between the minimum threshold and the maximum
threshold, one of the following three scenarios can occur:
• If the transmission endpoints are ECN-capable and traffic is congested, and the
WRED algorithm determines that the packet should have been dropped based
on the drop probability, the packet is transmitted and marked so the routers
know the system is congested and can slow transmission rates.
• If neither endpoint is ECN-capable, the packet may be dropped based on the
WRED drop probability. This behavior is the identical treatment that a packet
receives when WRED is enabled without ECN configured on the router.
• If the network is experiencing congestion, the packet is transmitted. No further
marking is required. When you enable wred-ecn, and the number of packets in
the queue is above the maximum threshold, packets are dropped based on the
drop probability. This behavior is the identical treatment a packet receives when
WRED is enabled without ECN configured on the router.
Example
Dellconf) #service-class wred ecn 0, 3-5, 7 backplane
show hardware stack-unit buffer
Display the counters for the specified port, minimum guaranteed buffer of a priority-group, and the
shared buffer. This command is supported on the S6000 platform.
Syntax
show hardware stack-unit <0-5> buffer unit <0-0> port {1-104 |
all} priority-group <0 -7> buffer-info
Parameters
stack-unit <0–
5>
Enter the keywords stack-unit to select a particular stack
member and then enter one of the following command
options to display a collection of data based on the option
entered. The range is 0 to 5.
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Quality of Service (QoS)