Configuring Shaping - Cisco Catalyst 3750 Software Configuration Manual

Chapter 26 Configuring QoS
Switch(config-pmap-c)# random-detect dscp af21 28 35 10
Switch(config-pmap-c)# random-detect dscp af22 26 35 10
Switch(config-pmap-c)# exit
Switch(config-pmap)# exit
Switch(config)# policy-map parent
Switch(config-pmap)# class vlan101
Switch(config-pmap-c)# bandwidth percent 20
Switch(config-pmap-c)# service-policy policy1
Switch(config-pmap-c)# exit
Switch(config-pmap)# exit
Switch(config)# interface gigabitethernet1/1/1
Switch(config-if)# service-policy output parent

Configuring Shaping

Shaping provides a process for delaying out-of-profile packets in queues so that they conform to a
specified profile. Shaping is distinct from policing. Policing drops packets that exceed a configured
threshold, but shaping buffers packets so that traffic remains within a threshold. Shaping offers greater
smoothness in handling traffic than policing. You can configure average-rate traffic shaping on a traffic
class within a policy map at the class level, at the VLAN level, and at the physical level by using the
shape policy-map class configuration command. At the physical level of the hierarchy, you can shape
only the class-default class in an egress policy attached to an ES port.
Before beginning this procedure, make sure that you have reviewed the configuration guidelines and
have created the class map to isolate traffic. For more information, see the
Configuration Guidelines" section on page 26-76
Maps" section on page
Beginning in privileged EXEC mode, follow these step to configure class-level shaping in a service
policy for outbound traffic. This procedure is optional. The examples that follow the procedure show
how to configure class-level, VLAN-level, and physical-level shaping.
Command
Step 1
configure terminal
Step 2 policy-map policy-map-name
Step 3 class class-name
Step 4
shape average cir-bps
Step 5 exit
Step 6
exit
78-15870-01
26-78.
Purpose
Enter global configuration mode.
Create a policy map by entering the policy-map name, and enter
policy-map configuration mode.
By default, no policy maps are defined.
Specify the name of the class whose traffic policy you want to create
or change, and enter policy-map class configuration mode.
By default, no traffic classes are defined.
Enable average-rate traffic shaping. Specify the committed
information rate, the bit rate that traffic is shaped to, in bps. This is the
access bit rate that you have contracted for with your service provider
or the service levels that you intend to maintain. The range is 64000 to
2000000000 bps.
Allocate the shaped rate in 100-kbps increments; otherwise, the
software rounds down the bandwidth to the nearest 100-kbps
increment.
By default, average-rate traffic shaping is disabled.
Return to policy-map configuration mode.
Return to global configuration mode.
Catalyst 3750 Metro Switch Software Configuration Guide
"Hierarchical QoS
and the "Classifying Egress Traffic by Using Class
Configuring Hierarchical QoS
26-99