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Configuring Voice QoS

Hi All

Received some great documentation from a collegue surrounding Voice & Video QoS for edge routers to ensure Voice and Video traffic is prioritised when connecting over a WAN

This also gives you the abiilty to mark traffic based on it’s protocol so if you QoS is not setup properly it will still mark it and send it correctly accross the WAN.


WAN Interface QOS To Use Low Latency Queuing (LLQ)

class-map match-any voice-signaling

 match  dscp cs3

class-map match-any video-traffic

 match  dscp cs4

class-map match-any voice-traffic

 match  dscp ef


policy-map WAN-EDGE-OUT

 class voice-traffic   <————– Voice traffic

   priority 5120

 class voice-signaling <————– Voice Signaling

   bandwidth 768

 class video-traffic  <————– Video traffic

   bandwidth 2048

 class class-default <————– All other traffic will have the rest of the bandwidth



interface GIG X/X

band 40000 <————– Sets Interface Bandwidth to 40Mbit

ip nbar protocol-discovery <————– Enables NBAR

service-policy input WAN-EDGE-OUT <————– Applies LLQ QOS policy


LAN Interface QoS To MARK Traffic.

ip access-list extended CISCO

 permit ip host “IP address” any


class-map match-any MARKING-video-traffic

 match access-group name CISCO

class-map match-any MARKING-voice-traffic

 match protocol rtp

class-map match-any MARKING-voice-signaling

 match protocol sip

 match protocol h323

 match protocol skinny


policy-map MARK-TRAFFIC

 class MARKING-voice-traffic <————– Mark voice traffic

   set dscp ef

 MARKING-voice-signaling <————– Mark voice signaling traffic

   set dscp cs3

 MARKING-video-traffic    <————– Mark video traffic

   set dscp cs4


Interface GIG X/X

ip nbar protocol-discovery  <————– Enables NBAR

Service-policy input MARK-TRAFFIC  <————– Applies marking QOS policy


Troubleshooting Commands

Use the following commands to display configured policies and class-maps:

Show policy-map [policy-map-name]

Show class-map [class-map-name]


Use the following command to display installed policies:

Show policy-map interface brief


Use the following command to display statistics of QOS policy applied in interface GIG X/X

Show policy-map interface GIG X/X


To display the statistics gathered by the Network-Based Application Recognition (NBAR) Protocol Discovery feature, use the show ip nbar protocol-discovery privileged EXEC command.

Show ip nbar protocol-discovery

Show ip nbar protocol-discovery [interface interface-spec] [stats {byte-count | bit-rate  | packet-count}][{protocol protocol-name | top-n number}]



The Voice Man

Categories: CME, CUCM, Gateways, UCCX Tags: , , , ,
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