3Com Switch 7750 Configuration Guide

Configuring Congestion Avoidance 675
n
Only non-type-A I/O Modules support the configuration for queue scheduling
mode.
Configuration Example
■ The switch adopts the WRR queue scheduling algorithm, and the weight values
of outbound queues are 10, 5, 10, 10, 5, 10, 5, and 10 respectively;
■ Display the configuration.
Configuration procedure:
<SW7750> system-view
[SW7750] interface GigabitEthernet 2/0/1
[SW7750-GigabitEthernet2/0/1] qos
[SW7750-qosb-GigabitEthernet2/0/1] queue-scheduler wrr 10 5 10 10 5 10 5 10
[SW7750-qosb-GigabitEthernet2/0/1] display qos-interface GigabitEthernet 2/0/1 qu
eue-scheduler
GigabitEthernet2/0/1:
Queue scheduling mode: weighted round robin
weight of queue 1: 10
weight of queue 2: 5
weight of queue 3: 10
weight of queue 4: 10
weight of queue 5: 5
weight of queue 6: 10
weight of queue 7: 5
weight of queue 8: 10
COS configuration:
Config (max queues): 8
Schedule mode: weighted round-robin
Weighting (in packets):
COSQ 0 = 10 packets
COSQ 1 = 5 packets
COSQ 2 = 10 packets
COSQ 3 = 10 packets
COSQ 4 = 5 packets
COSQ 5 = 10 packets
COSQ 6 = 5 packets
COSQ 7 = 10 packets
Egress port queue statistics(in bytes):
Priority CosQ Threshold Count Used(%):
0 2 18432 0 0
1 0 2560 0 0
2 1 2560 0 0
3 3 2560 0 0
4 4 2560 0 0
5 5 2560 0 0
6 6 2560 0 0
7 7 2560 0 0
common queue statistics(in bytes):
49152 0 0
Configuring
Congestion Avoidance
When congestion happens, the switch will drop packets as soon as possible to
release queue resources and try not to put packets into high-delay queues in order
to eliminate congestion. The switch adopts the RED algorithm for congestion
avoidance.
Configuration
Prerequisites
■ The indexes of queues to be dropped at random, the queue length that starts
the drop action, the queue length that causes all the packets to be dropped
and the drop probability are specified
■ The ports that need this configuration are specified