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Understanding Junos OS EZQoS for CoS Configurations on EX Series Switches

Junos operating system (Junos OS) EZQoS on Juniper Networks EX Series Ethernet Switches eliminates the complexities involved in configuring class of service (CoS) across the network. EZQoS offers templates for key traffic classes.

Junos OS CoS allows you to divide traffic into classes and offer various levels of throughput and packet loss when congestion occurs. You can use CoS to ensure that different types of traffic (voice, video, and data) get the bandwidth and consideration they need to meet user expectations and business objectives.

Configuring CoS requires careful consideration of your service needs and thorough planning and design to ensure consistency across all switches in a CoS domain. To configure CoS manually, you must define and fine-tune all CoS components such as classifiers, rewrite rules, forwarding classes, schedulers, and scheduler-maps and then apply these components to the interfaces. Therefore, configuring CoS can be a fairly complex and time-consuming task.

EZQoS works by automatically assigning preconfigured values to all CoS parameters based on the typical application requirements. These preconfigured values are stored in a template with a unique name. You can change the preconfigured values of these parameters to suit your particular application needs.

For using EZQoS, you must identify which switch ports are being used for a specific application (such as VoIP, video, and data) and manually apply the corresponding application-specific EZQoS template to these switch ports.


Currently, we provide an EZQoS template for configuring CoS for VoIP.


We recommend that you do not use the term EZQoS for defining a classifier.