Enterprise QoS Solution Reference Network Design Guide
Enterprise QoS Solution Reference Network Design Guide
Enterprise QoS Solution Reference Network Design Guide
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Chapter 2 Campus <strong>QoS</strong> <strong>Design</strong><br />
Version 3.3<br />
Catalyst 4500 Supervisor II+/III/IV/V—<strong>QoS</strong> Considerations and <strong>Design</strong><br />
CAT4500-SUP4(config-pmap)#exit<br />
CAT4500-SUP4(config)#<br />
CAT4500-SUP4(config)#interface range FastEthernet2/1 - 48<br />
CAT4500-SUP4(config-if-range)# service-policy output DBL ! Applies DBL policy<br />
CAT4500-SUP4(config-if-range)# tx-queue 3<br />
CAT4500-SUP4(config-if-tx-queue)# priority high ! Enables Q3 as PQ<br />
CAT4500-SUP4(config-if-tx-queue)# shape percent 30 ! Shapes PQ to 30%<br />
CAT4500-SUP4(config-if-tx-queue)# exit<br />
CAT4500-SUP4(config-if-range)#exit<br />
CAT4500-SUP4(config)#<br />
CAT4500-SUP4(config)#interface range GigabitEthernet1/1 - 2<br />
CAT4500-SUP4(config-if-range)# service-policy output DBL ! Applies DBL policy<br />
CAT4500-SUP4(config-if-range)# tx-queue 1<br />
CAT4500-SUP4(config-if-tx-queue)# bandwidth percent 5 ! Q1 gets 5%<br />
CAT4500-SUP4(config-if-tx-queue)# tx-queue 2<br />
CAT4500-SUP4(config-if-tx-queue)# bandwidth percent 25 ! Q2 gets 25%<br />
CAT4500-SUP4(config-if-tx-queue)# tx-queue 3<br />
CAT4500-SUP4(config-if-tx-queue)# priority high ! Enables Q3 as PQ<br />
CAT4500-SUP4(config-if-tx-queue)# bandwidth percent 30 ! PQ gets 30%<br />
CAT4500-SUP4(config-if-tx-queue)# shape percent 30 ! Shapes PQ to 30%<br />
CAT4500-SUP4(config-if-tx-queue)# tx-queue 4<br />
CAT4500-SUP4(config-if-tx-queue)# bandwidth percent 40 ! Q4 gets 40%<br />
CAT4500-SUP4(config-if-tx-queue)#end<br />
CAT4500-SUP4#<br />
Catalyst 4500 <strong>QoS</strong> Verification Commands<br />
show qos dbl<br />
Catalyst 4500 <strong>QoS</strong> verification commands for queuing include the following:<br />
show qos dbl<br />
show qos maps dscp tx-queue<br />
show qos interface<br />
The Catalyst 4500 show qos dbl verification command returns whether or not DBL has been enabled,<br />
as well as some of the operating parameters that have been defined for its operation. These parameters<br />
include allowing DBL to set RFC 3168 ECN bits in IP headers, as shown in the example below.<br />
Example 2-43 Show <strong>QoS</strong> DBL Verification for a Catalyst 4500 Switch<br />
CAT4500-SUP4#show qos dbl<br />
QOS is enabled globally<br />
DBL is enabled globally<br />
DBL flow includes vlan<br />
DBL flow includes layer4-ports<br />
DBL uses ecn to indicate congestion<br />
DBL exceed-action probability: 15%<br />
DBL max credits: 15<br />
DBL aggressive credit limit: 10<br />
DBL aggressive buffer limit: 2 packets<br />
CAT4500-SUP4#<br />
<strong>Enterprise</strong> <strong>QoS</strong> <strong>Solution</strong> <strong>Reference</strong> <strong>Network</strong> <strong>Design</strong> <strong>Guide</strong><br />
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