Rate and give feedback:  Feedback Received. Thank You!

Rate and give feedback: 

X

This document helped resolve my issue

Yes No

Additional Comments

800 characters remaining

May we contact you if necessary?

Name:  

E-mail: 

Enter a valid Email ID

Need product assistance? Contact Juniper Support

Submit

This site is protected by hCaptcha and its Privacy Policy and Terms of Service apply.

English  

English

Example: Configuring Minimum Guaranteed Output Bandwidth

Requirements

• A Juniper Networks QFX3500 Switch
• Junos OS Release 11.1 or later for the QFX Series

Overview

The priority group minimum guaranteed bandwidth defines the minimum total amount of bandwidth available for all of the queues in the priority group to meet their minimum bandwidth requirements.

The transmit-rate setting in the scheduler configuration determines the minimum guaranteed bandwidth for an individual queue. The transmit rate also determines the amount of excess (extra) priority group bandwidth that the queue can share. Extra priority group bandwidth is allocated among the queues in the priority group in proportion to the transmit rate of each queue.

The guaranteed-rate setting in the traffic control profile configuration determines the minimum guaranteed bandwidth for a priority group. The guaranteed rate also determines the amount of excess (extra) port bandwidth that the priority group can share. Extra port bandwidth is allocated among the priority groups on a port in proportion to the guaranteed rate of each priority group.

Note: You must configure both the transmit-rate value for the queue and the guaranteed-rate value for the priority group in order to set a valid minimum bandwidth guarantee for a queue. (If the priority group does not have a guaranteed minimum bandwidth, there is no guaranteed bandwidth pool from which the queue can take its guaranteed minimum bandwidth.) The sum of the queue transmit rates in a priority group should not exceed the guaranteed rate for the priority group. (You cannot guarantee a minimum bandwidth for the queues that is greater than the minimum bandwidth guaranteed for the entire set of queues.)

Note: When you configure bandwidth for a queue or a priority group, the switch considers only the data as the configured bandwidth. The switch does not account for the bandwidth consumed by the preamble and the interframe gap (IFG). Therefore, when you calculate and configure the bandwidth requirements for a queue or for a priority group, consider the preamble and the IFG as well as the data in the calculations.

Note: You cannot configure minimum guaranteed bandwidth on strict-high priority queues or on a priority group that contains strict-high priority queues.

• Configure a transmit rate (minimum guaranteed queue bandwidth) of 2 Gbps for queues in a scheduler named be-sched.
• Configure a guaranteed rate (minimum guaranteed priority group bandwidth) of 4 Gbps for a priority group in a traffic control profile named be-tcp.
• Assign the scheduler to a queue named best-effort by using a scheduler map named be-map.
• Associate the scheduler map be-map with the traffic control profile be-tcp.
• Assign the queue best-effort to a priority group named be-pg.
• Assign the priority group and the minimum guaranteed bandwidth scheduling to the egress interface xe-0/0/7.

Table 1 shows the configuration components for this example:

Configuring Guaranteed Minimum Bandwidth

1. Configure the minimum guaranteed queue bandwidth of 2 Gbps for scheduler be-sched:
   [edit class-of-service schedulers]
user@switch# set be-sched transmit-rate 2g

   
   

2. Configure the minimum guaranteed priority group bandwidth of 4 Gbps for traffic control profile be-tcp:
   [edit class-of-service traffic-control-profiles]
user@switch# set be-tcp guaranteed-rate 4g

   
   

3. Associate the scheduler be-sched with the best-effort queue in the scheduler map be-map:
   [edit class-of-service scheduler-maps]
user@switch# set be-map forwarding-class best-effort scheduler be-sched

   
   

4. Associate the scheduler map with the traffic control profile:
   [edit class-of-service traffic-control-profiles]
user@switch# set be-tcp scheduler-map be-map

   
   

5. Assign the best-effort queue to the priority group be-pg:
   [edit class-of-service forwarding-class-sets]
user@switch# set be-pg class best-effort

   
   

6. Apply the configuration to interface xe-0/0/7:
   [edit class-of-service interfaces]
user@switch# set xe-0/0/7 forwarding-class-set be-pg output-traffic-control-profile be-tcp

   
   

Verification

To verify the minimum guaranteed output bandwidth configuration, perform these tasks:

• Verifying the Minimum Guaranteed Queue Bandwidth
• Verifying the Priority Group Minimum Guaranteed Bandwidth and Scheduler Map Association
• Verifying the Scheduler Map Configuration
• Verifying Queue (Forwarding Class) Membership in the Priority Group
• Verifying the Egress Interface Configuration

Verifying the Minimum Guaranteed Queue Bandwidth

Purpose

Verify that you configured the minimum guaranteed queue bandwidth as 2g in the scheduler be-sched.

Action

Display the minimum guaranteed bandwidth in the be-sched scheduler configuration using the operational mode command show configuration class-of-service schedulers be-sched transmit-rate:

2g;

Verifying the Priority Group Minimum Guaranteed Bandwidth and Scheduler Map Association

Purpose

Verify that the minimum guaranteed priority group bandwidth is 4g and the attached scheduler map is be-map in the traffic control profile be-tcp.

Action

Display the minimum guaranteed bandwidth in the be-tcp traffic control profile configuration using the operational mode command show configuration class-of-service traffic-control-profiles be-tcp guaranteed-rate:

4g;

Display the scheduler map in the be-tcp traffic control profile configuration using the operational mode command show configuration class-of-service traffic-control-profiles be-tcp scheduler-map:

scheduler-map be-map;

Verifying the Scheduler Map Configuration

Purpose

Verify that the scheduler map be-map maps the forwarding class best-effort to the scheduler be-sched.

Action

Display the be-map scheduler map configuration using the operational mode command show configuration class-of-service schedulers maps be-map:

forwarding-class best-effort scheduler be-sched;

Verifying Queue (Forwarding Class) Membership in the Priority Group

Purpose

Verify that the forwarding class set be-pg includes the forwarding class best-effort.

Action

Display the be-pg forwarding class set configuration using the operational mode command show configuration class-of-service forwarding-class-sets be-pg:

class best-effort;

Verifying the Egress Interface Configuration

Purpose

Verify that the forwarding class set be-pg and the traffic control profile be-tcp are attached to egress interface xe-0/0/7.

Action

Display the egress interface using the operational mode command show configuration class-of-service interfaces xe-0/0/7:

forwarding-class-set {
    be-pg {
        output-traffic-control-profile be-tcp;
    }
}