Queue-Limit - Cisco NCS 540 Series Routers Command Reference Manual

queue-limit

queue-limit
To specify or modify the maximum number of packets the queue can hold for a class policy configured in a
policy map for each port, use the queue-limit command in policy map class configuration mode. To remove
the queue packet limit from a class, use the no form of this command.
queue-limit value [unit ] | percent <1-100>
no queue-limit
Syntax Description
value
unit
percent
The default value is 10 milliseconds for all queues including the high-priority queues.
Command Default
Policy map class configuration
Command Modes
Command History
Release
Release 6.0
When configuring the queue-limit command, you must configure one of the following commands: priority,
Usage Guidelines
shape average, bandwidth or bandwidth remaining, except for the default class. The default value is 10
milliseconds for all queues including the high-priority queues.
The queue-limit command is supported only in the egress direction.
Packets satisfying the match criteria for a class accumulate in the queue reserved for the class until they are
serviced by the scheduling mechanism. The queue-limit command defines the maximum threshold for a
class. When that threshold is reached, enqueued packets to the class queue result in tail drop (packet drop).
Modular QoS Command Reference for Cisco NCS 5500 Series and Cisco NCS 540 Series Routers
68
Maximum threshold for tail drop in bytes. Range is from 1 to 4294967295.
(Optional) Units for the queue limit value. Values can be:
• bytes —bytes
• kbytes —kilobytes
• mbytes —megabytes
• ms —milliseconds
• packets —packets (default)
• us —microseconds
Note When the specified units is packets, packets are assumed to be 256 bytes in size.
(Optional) Allows you to specify queue limit thresholds as a percentage of the total buffer limit for
each port. This makes your provisioning model simpler and makes it easier for you to adjust the
queue burst limit, irrespective of the queue's service rate. The calculation is based on the assumption
that a port takes 40 milli-seconds of buffering at port-rate. This option was introduced in Release
6.1.2.
Congestion Avoidance Commands
Modification
This command was introduced.