Quality of Service (QoS): Managing Bandwidth More Effectively

Using QoS Classifiers To Configure QoS for Outbound Traffic

Options for Assigning Priority. Priority control options for TCP or UDP packets carrying a specified TCP or UDP port number include:

802.1p priority

DSCP policy (Assigning a new DSCP and an associated 802.1p priority; inbound packets must be IPv4.)

For a given TCP or UDP port number, you can use only one of the above options at a time. However, for different port numbers, you can use different options.

TCP/UDP Port Number Ranges. There are three ranges:

Well-Known Ports: 0 - 1023

Registered Ports: 1024 - 49151

Dynamic and/or Private Ports: 49152 - 65535

For more information, including a listing of UDP/TCP port numbers, go to the Internet Assigned Numbers Authority (IANA) website at:

www.iana.org

Then click on:

Protocol Number Assignment Services

P (Under “Directory of General Assigned Numbers” heading)

Port Numbers

Assigning 802.1p Priority Based on TCP or UDP Port Number

This option assigns an 802.1p priority to (IPv4) TCP or UDP packets as described below.

Syntax: qos < udp-port tcp-port > < tcp or udp port number > priority < 0 - 7 >

Configures an 802.1p priority for outbound packets having the specified TCP or UDP application port number. This priority determines the packet’s queue in the outbound port to which it is sent. If the packet leaves the switch on a tagged port, it carries the 802.1p priority with it to the next downstream device. (Default: Disabled)

6-22