Quality of Service (QoS): Managing Bandwidth More Effectively 
Using QoS Classifiers To Configure QoS for Outbound Traffic 
Note   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-override in 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-override for 
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. 
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