Juniper JUNOSE 11.1.X - QUALITY OF SERVICE CONFIGURATION GUIDE 3-21-2010 Configuration Manual page 55

NOTE: If the sum of the queue minimum lengths is greater than the amount of
egress buffer memory, then the egress buffer memory is oversubscribed.
To configure a minimal level of buffering or to limit the buffering in queues, set
a maximum queue length. For example, if you want to control latency by
configuring very small queues, set the maximum queue length to 256 bytes. The
system queues no more than 256 bytes.
If you do not set the queue lengths, the router varies the queue length dynamically
in the range 1 KB–7 MB.
Create a queue profile and enter Queue Configuration mode.
1.
host1(config)#queue-profile video
host1(config-queue)#
You can configure 16 queue profiles on an E Series router.
(Optional) Set the buffer weight of the queue.
2.
host1(config-queue)#buffer-weight 16
Queues with a buffer weight of 16 are twice as long as queues with a buffer weight
of 8. The range is 1 63; the default is 8.
(Optional) Set a minimum or maximum queue length for committed packets.
3.
host1(config-queue)#committed-length 11000 15000
The range of minimum and maximum lengths is 0 1 GB. By default, there is no
minimum or maximum length. The color for committed packets is green.
(Optional) Set a minimum or maximum queue length for conformed packets.
4.
host1(config-queue)#conformed-length 10000 14000
The range of minimum and maximum lengths is 0 1 GB. By default, there is no
minimum or maximum length. The color for conformed packets is yellow.
(Optional) Set a minimum or maximum queue length for exceeded packets.
5.
host1(config-queue)#exceeded-length 9000 10000
The range of minimum and maximum lengths is 0 1 GB. By default, there is no
minimum or maximum length. The color for exceeded packets is red.
(Optional) Set the conformed drop threshold as a percentage of the committed
6.
threshold.
host1(config-queue)#conformed-fraction 60
The range is 0–100 percent; the default is 50.
(Optional) Set the exceeded drop threshold as a percentage of the committed
7.
threshold.
host1(config-queue)#exceeded-fraction 40
The range is 0–100 percent; the default is 25.
Configuring Queue Profiles to Manage Buffers and Thresholds
Chapter 3: Configuring Queue Profiles for Buffer Management
23