Congestion Avoidance; Congestion Management; Virtualization Support; Licensing Requirements - Cisco Nexus 7000 Series Configuration Manual

Congestion Avoidance

Congestion Avoidance
You can use the following methods to proactively avoid traffic congestion on the device:
• Apply WRED to a class of traffic, which allows the device to drop packets based on the CoS field. WRED
• Apply tail drop to a class of traffic, which allows the device to drop packets based on the CoS field.
• Apply WRED to a class of traffic, which allows the device to drop packets based on the DSCP field.
• Apply tail drop to a class of traffic, which allows the device to drop packets based on the DSCP field.
For information about configuring congestion avoidance, see the "Modifying Queuing Class Maps for DSCP"
section.

Congestion Management

For ingress packets, you can configure congestion management by specifying a bandwidth that allocates a
minimum data rate to a queue.
For egress packets, you can choose one of the following congestion management methods:
• Specify a bandwidth that allocates a minimum data rate to a queue.
• Impose a maximum data rate on a class of traffic so that excess packets are retained in a queue to shape
• Allocate all data for a class of traffic to a priority queue. The device distributes the remaining bandwidth
For information about configuring congestion management, see the "Configuring WRED by DSCP Values"
section.

Virtualization Support

A VDC is a logical representation of a set of system resources. Other than configuring class maps, queuing
and scheduling apply only to the VDC where the commands are entered. For information about configuring
class maps, see the "Modifying Queuing Class Maps for COS" section.
For information about configuring VDCs, see the Cisco Nexus 7000 Series NX-OS Virtual Device Context
Configuration Guide.

Licensing Requirements

The QoS feature does not a require license. Any feature not included in a license package is bundled with the
Cisco NX-OS system images and is provided at no extra charge to you.
Using virtual device contexts (VDCs) requires an Advanced Services license.
For a complete explanation of the Cisco NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
Cisco Nexus 7000 Series NX-OS Quality of Service Configuration Guide
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is designed to work with TCP traffic.
WRED is designed to work with TCP traffic.
the output rate.
among the other queues.
Configuring Queuing and Scheduling on M-Series I/O Modules