3-24
Cisco AVVID Network Infrastructure Enterprise Quality of Service Design
956467
Chapter 3 QoS in an AVVID-Enabled Campus Network
Selecting an Access-Layer Switch
Step 1
Specify the transmit queue.
4006-SUPIII-Access(config-if-tx-queue)#tx-queue 3
Step 2
Set the priority to high.
4006-SUPIII-Access(config-if-tx-queue)#priority high
Configuring ACLs
There are times when classification of traffic by the access-layer switch is required. The Catalyst 4000
with Supervisor III has a powerful set of features that allow traffic to be classified as it enters the
network.
To classify VoIP bearer and control traffic as it enters the network, do the following:
Step 1
Create an ACL to match the traffic to be prioritized.
4006-SUPIII-Access(config)#ip access-list extended GOLD-DATA
4006-SUPIII-Access(config-ext-nacl)#remark Match IP Address of the application server
4006-SUPIII-Access(config-ext-nacl)#permit ip any host 192.168.100.1
4006-SUPIII-Access(config-ext-nacl)#permit ip host 192.168.100.1 any
4006-SUPIII-Access(config)#ip access-list extended VOICE
4006-SUPIII-Access(config-ext-nacl)#remark Match the UDP ports that VoIP Uses for Bearer
Traffic
4006-SUPIII-Access(config-ext-nacl)#permit udp any any range 16384 32767
4006-SUPIII-Access(config)#ip access-list extended VOICE-CONTROL
4006-SUPIII-Access(config-ext-nacl)#remark Match VoIP Control Traffic
4006-SUPIII-Access(config-ext-nacl)#remark SCCP
4006-SUPIII-Access(config-ext-nacl)#permit tcp any any range 2000 2002
4006-SUPIII-Access(config-ext-nacl)#remark H323 Fast Start
4006-SUPIII-Access(config-ext-nacl)#permit tcp any any eq 1720
4006-SUPIII-Access(config-ext-nacl)#remark H323 Slow Start
4006-SUPIII-Access(config-ext-nacl)#permit tcp any any range 11000 11999
4006-SUPIII-Access(config-ext-nacl)#remark H323 MGCP
4006-SUPIII-Access(config-ext-nacl)#permit udp any any eq 2427
Step 2
Create classes based on the ACL.
4006-SUPIII-Access(config)#class-map match-all GOLD-DATA
4006-SUPIII-Access(config-cmap)#description Mission Critical Traffic
4006-SUPIII-Access(config-cmap)#match access-group name GOLD-DATA
4006-SUPIII-Access(config)#class-map match-all VOICE
4006-SUPIII-Access(config-cmap)#description VoIP Bearer Traffic
4006-SUPIII-Access(config-cmap)#match access-group name VOICE
4006-SUPIII-Access(config)#class-map match-all VOICE-CONTROL
4006-SUPIII-Access(config-cmap)#description VoIP Control Traffic (SCCP, H225, H254, MGCP)
4006-SUPIII-Access(config-cmap)#match access-group name VOICE-CONTROL
Step 3
Create a policy to set the DSCP PHB label for the classes.
4006-SUPIII-Access(config)#policy-map ACCESS-C4006-LAN-EDGE-IN
4006-SUPIII-Access(config-pmap)#description Set DSCP PerHopBehavior Label for VOIP Control
and Bearer Traffic
4006-SUPIII-Access(config-pmap)#class VOICE-CONTROL
4006-SUPIII-Access(config-pmap-c)#set ip dscp 26
4006-SUPIII-Access(config-pmap)#class VOICE
4006-SUPIII-Access(config-pmap-c)#set ip dscp 46
4006-SUPIII-Access(config-pmap)#class GOLD-DATA
4006-SUPIII-Access(config-pmap-c)#set ip dscp 18