Traffic Shaping; Licensing Requirements For Queuing And Scheduling; Prerequisites For Queuing And Scheduling - Cisco Nexus 9000 Series Configuration Manual

Configuring Queuing and Scheduling

Traffic Shaping

Traffic shaping allows you to control the traffic going out of an interface in order to match its flow to the
speed of the remote target interface and to ensure that the traffic conforms to policies contracted for it. You
can shape traffic that adheres to a particular profile to meet downstream requirements. Traffic shaping eliminates
bottlenecks in topologies with data-rate mismatches.
Traffic shaping regulates and smooths out the packet flow by imposing a maximum traffic rate for each port's
egress queue. Packets that exceed the threshold are placed in the queue and are transmitted later. Traffic
shaping is similar to traffic policing, but the packets are not dropped. Because packets are buffered, traffic
shaping minimizes packet loss (based on the queue length), which provides better traffic behavior for TCP
traffic.
Using traffic shaping, you can control access to available bandwidth, ensure that traffic conforms to the policies
established for it, and regulate the flow of traffic to avoid congestion that can occur when the egress traffic
exceeds the access speed of its remote, target interface. For example, you can control access to the bandwidth
when policy dictates that the rate of a given interface should not, on average, exceed a certain rate even though
the access rate exceeds the speed.
Queue length thresholds are configured using the WRED configuration.
Traffic shaping is not supported on ALE enabled device 40G front panel ports. When traffic shaping is
Note
configured for the system level, the setting is ignored and no error message is displayed. When traffic
shaping commands are configured for the port level, the setting is rejected and an error message is displayed.

Licensing Requirements for Queuing and Scheduling

The following table shows the licensing requirements for this feature:
Product
Cisco NX-OS

Prerequisites for Queuing and Scheduling

Queuing and scheduling have the following prerequisites:
• You must be familiar with using modular QoS CLI.
• You are logged on to the device.
Cisco Nexus 9000 Series NX-OS Quality of Service Configuration Guide, Release 7.x
License Requirement
The QoS feature does not a require license. Any
feature not included in a license package is bundled
with the NX-OS image and is provided at no extra
charge to you. For a complete explanation of the
Cisco NX-OS licensing scheme, see the
Licensing Guide.

Traffic Shaping

Cisco NX-OS
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