3Com 3500 manual Qos classifier define, Defines a flow or nonflow classifier

694CHAPTER 22: QUALITY OF SERVICE (QOS) AND RSVP

qos classifier define

✓3500

✓9000

9400

3900

9300

For CoreBuilder 9000: Applies to Layer 3 switching modules only.

Defines a flow or nonflow classifier.

Valid Minimum Abbreviation

q cl def

Important Considerations

■Classifiers define how the system groups packets so that it can schedule them with the appropriate service level. QoS supports flow and nonflow classifiers:

■Flow classifiers apply to routed IP multicast and IP unicast packets. You can define up to 100 flow classifiers. Each filter (address and port pattern) in a flow classifier counts toward the limit.

■Nonflow classifiers apply to bridged or routed traffic that is associated with a specific protocol (IP, TCP/IP, IPX, and AppleTalk) or to a custom protocol (Ethertype or Destination Service Access Point/Source Service Access Point (DSAP/SSAP). You can also use them to apply IEEE 802.1p tag values to forwarded frames. You can define up to 16 nonflow classifiers. All 16 nonflow classifiers are in use by default.

■The default classifier number is 499. You cannot remove or modify this default classifier. However, you can remove any of the predefined classifiers (for example, if you need another nonflow classifier). See “qos classifier remove” later in this chapter for more information.

■When you define a filter (address and port pattern) for a flow classifier, select a source and destination start and end port ranges that are as small as possible (for example, a single port). If the classifier applies to a wide range of Transmission Control Protocol (TCP) or User Datagram Protocol (UDP) ports, you increase the amount of classified traffic on the system and consume valuable QoS resources.

■A classifier can have only one control applied to it.

■If you select custom when you define a nonflow classifier, you are prompted to select the protocol by Ethertype or DSAP/SSAP. After you select a protocol, you are prompted to provide the hexidecimal ranges.

Depending on the number of VLANs defined, you can define a maximum of 3 custom protocols that can have controls applied to them. This limitation does not apply to non-controlled custom protocols.