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
Dell(conf)#service-class wred ecn 0, 3-5, 7 backplane
service-pool wred
Configure a global buffer pool that serves as a shared buffer accessed by multiple queues when the
minimum guaranteed buffers for a queue are consumed.
The Z9500 supports four global service-pools in the egress direction. Two service pools are used—one
for lossy queues and the other for lossless (priority-based flow control (PFC)) queues. You can enable
WRED and ECN operation on the global service-pools. You can define WRED profiles and weight on each
of the global service-pools for both lossy and lossless (PFC) service-pools.
Z9500
Syntax
[no] buffer-pool wred {green | weight | yellow} {[pool0
number/
string
] || [pool1
number/string
]}
Parameters
buffer-pool
Define the mapping between the service class and policy-
based QoS or routing.
wred
Specify WRED curve parameters for a queue.
green
Specify green (low) drop precedence to a queue.
weight
Specify a weight factor to a queue
yellow
Specify yellow (medium) drop precedence to a queue
pool0
Service-pool buffer 1 (default service-pool for PFC traffic)
pool1
Service-pool buffer 0 (default service-pool for lossy traffic)
number
Enter a weight for the queue as a number in the range of 1 to
15. This parameter applies only if you specify the green or
yellow drop precedence.
string
Enter the WRED profile name. It is a string of up to 32
characters. Or use one of the five pre-defined WRED profile
names. Pre-defined Profiles: wred_drop, wred-ge_y,
wred_ge_g, wred_teng_y, wred_teng_. This parameter
applies only if you specify a weight factor.
Default
All queues on backplane ports operate in tail-drop (best-effort traffic) mode by
default. There is no default WRED green or yellow profile. The default weight is 0.
Command
Modes
CONFIGURATION mode
1480
Quality of Service (QoS)
