Configuring CoS Classifiers (NSM Procedure)
Packet classification associates incoming packets with a particular class-of-service (Cos) servicing level. Classifiers associate packets with a forwarding class and loss priority and, based on the associated forwarding class, assign packets to output queues. JUNOS software supports two general types of classifiers:
- Behavior aggregate or CoS value traffic classifiers—Examines the CoS value in the packet header. The value in this single field determines the CoS settings applied to the packet. BA classifiers allow you to set the forwarding class and loss priority of a packet based on the Differentiated Services code point (DSCP) value, IP precedence value, and IEEE 802.1p value. The default classifier is based on the DSCP value.
- Multifield traffic classifiers—Examines multiple fields in the packet such as source and destination addresses and source and destination port numbers of the packet. With multifield classifiers, you set the forwarding class and loss priority of a packet based on firewall filter rules.
To configure and apply behavior aggregate classifiers for the switch:
- In the navigation tree, select Device Manager > Devices.
- Click the Device Tree tab, and then double-click the device for which you want to configure and apply behavior aggregate classifiers.
- Click the Configuration tab. In the configuration tree expand Class of Service.
- Select Classifiers.
- Add or modify settings as specified in Table 1.
- Click one:
- OK—Saves the changes.
- Cancel—Cancels the modifications.
![]() | Note: After you make changes to a device configuration, you must push that updated device configuration to the physical security device for those changes to take effect. You can update multiple devices at one time. See the Network and Security Manager Administration Guide for more information. |
Table 1: Configuring and Applying Behavior Aggregate Classifiers
Task | Action |
|---|---|
Configure behavior aggregate classifiers for DiffServ CoS. |
|
Configure a best-effort forwarding class classifier. |
|
Configure an expedited forwarding class classifier. |
|
Configure an assured forwarding class classifier. |
|
Apply the behavior aggregate classifier to an interface. |
|
Related Topics
- Configuring CoS Code Point Aliases (NSM Procedure)
- Configuring CoS Drop Profile (NSM Procedure)
- Configuring CoS Forwarding Classes (NSM Procedure)
- Configuring CoS Interfaces (NSM Procedure)
- Configuring CoS Rewrite Rules (NSM Procedure)
- Configuring CoS Schedulers (NSM Procedure)
- Configuring CoS and Applying Scheduler Maps (NSM Procedure)

