Quality of Service (QoS): Managing Bandwidth More Effectively

 

Using QoS Classifiers To Configure QoS for Outbound Traffic

 

 

N o t e

A codepoint must have an 802.1p priority assignment (0 - 7) before you can

 

configure a policy for prioritizing packets by TCP or UDP port numbers. If a

 

codepoint you want to use shows No-overridein the Priority column of the

 

DSCP map (show qos dscp-map), then you must assign a 0 - 7 priority before

 

proceeding.

 

4. Configure the switch to assign the DSCP policy to packets with the

 

 

specified TCP or UDP port number.

 

Syntax: qos dscp-map < codepoint > priority < 0 - 7 >

 

This command is optional if a priority has already

 

been assigned to the < codepoint >. The command creates

 

a DSCP policy by assigning an 802.1p priority to a

 

specific DSCP. When the switch applies this policy to a

 

packet, the 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. For

 

IPv4 packets, the DSCP will be replaced by the codepoint

 

specified in this command. (Default: No-overridefor

 

most codepoints. See table 6-11 on page 6-59.)

 

Syntax: qos < udp-port tcp-port > < tcp or udp port number > dscp < codepoint >

 

Assigns a DSCP policy to outbound packets having the

 

specified TCP or UDP application port number and

 

overwrites the DSCP in these packets with the assigned

 

<codepoint > value. This policy includes an 802.1p

 

priority and determines the packet’s queue in the

 

outbound port to which it is sent. (The <codepoint > must

 

be configured with an 802.1p setting. See step 3 on page

 

6-24.)If the packet leaves the switch on a tagged port,

 

it carries the 802.1p priority with it to the next

 

downstream device. (Default: No-override)

 

no qos < udp-port tcp-port > < tcp-udp port number >

 

Deletes the specified UDP or TCP port number as a QoS

 

classifier.

 

show qos tcp-udp-port-priority

 

Displays a listing of all TCP and UDP QoS classifiers

 

currently in the running-config file.

6-25