Technical Documentation

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:

  1. In the navigation tree, select Device Manager > Devices.
  2. Click the Device Tree tab, and then double-click the device for which you want to configure and apply behavior aggregate classifiers.
  3. Click the Configuration tab. In the configuration tree expand Class of Service.
  4. Select Classifiers.
  5. Add or modify settings as specified in Table 1.
  6. 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.

  1. Click Add new entry next to Dscp.
  2. In the Name box, type the name of the behavior aggregate classifier—for example, ba-classifier.
  3. In the Import box, type the name of the default DSCP map.

Configure a best-effort forwarding class classifier.
  1. Click Add new entry next to Forwarding class.
  2. In the Class name box, type the name of the previously configured best-effort forwarding class—for example, be-class.
  3. Click Add new entry next to Loss priority.
  4. From the Loss val list, select high.
  5. Click Add new entry next to Code points.
  6. In the Value box, type the value of the high-priority code point for best-effort traffic—for example, 00001.
  7. Click OK three times.

Configure an expedited forwarding class classifier.
  1. Click Add new entry next to Forwarding class.
  2. In the Class name box, type the name of the previously configured expedited forwarding—for example, class-ef-class.
  3. Click Add new entry next to Loss priority.
  4. From the Loss val list, select high.
  5. Click Add new entry next to Code points.
  6. In the Value box, type the value of the high-priority code point for expedited forwarding traffic—for example, 101111.
  7. Click OK three times.

Configure an assured forwarding class classifier.
  1. Click Add new entry next to Forwarding class.
  2. In the Class name box, type the name of the previously configured assured forwarding—for example, class-af-class.
  3. Click Add new entry next to Loss priority.
  4. From the Loss val list, select high.
  5. Click Add new entry next to Code points.
  6. In the Value box, type the value of the high-priority code point for assured forwarding traffic—for example, 001100.
  7. Click OK three times.

Apply the behavior aggregate classifier to an interface.
  1. Click Add new entry next to Interfaces.
  2. In the Interface name box, type the name of the interface—for example, ge-0/0/0.
  3. Click Add new entry next to Unit.
  4. In the Unit number box, type the logical interface unit number—for example, 0.
  5. Click Configure next to Classifiers.
  6. In the Classifiers box, under Dscp, type the name of the previously configured behavior aggregate classifier—for example, ba-classifier.
  7. Click OK.

Published: 2009-08-23