Cisco 500 Series Administration Manual page 615

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STEP 4
STEP 5
STEP 6
NOTE
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This page enables shaping the egress for up to eight queues on each interface.
Select the Interface.
For each queue that is required, enter the following fields:
• Enable Shaping—Select to enable egress shaping on this queue
• Committed Information Rate (CIR)—Enter the maximum rate (CIR) in Kbits
per second (Kbps). CIR is the average maximum amount of data that can be
sent.
• Committed Burst Size (CBS)—Enter the maximum burst size (CBS) in bytes.
CBS is the maximum burst of data allowed to be sent even if a burst exceeds
CIR.
Click Apply. The bandwidth settings are written to the Running Configuration file.
VLAN Ingress Rate Limit
The VLAN Rate Limit feature is not available when the device is in Layer 3 mode.
Rate limiting per VLAN, performed in the VLAN Ingress Rate Limit page, enables
traffic limiting on VLANs. When VLAN ingress rate limiting is configured, it limits
aggregate traffic from all the ports on the device.
The following constraints apply to rate limiting per VLAN:
• It has lower precedence than any other traffic policing defined in the
system. For example, if a packet is subject to QoS rate limits but is also
subject to VLAN rate limiting, and the rate limits conflict, the QoS rate limits
take precedence.
• It is applied at the device level and within the device at the packet
processor level. If there is more than one packet processor on the device,
the configured VLAN rate limit value is applied to each of the packet
processors, independently. Devices with up to 24 ports have a single
packet processor, while devices of 48 ports or more have two packet
processors.
Rate limiting is calculated separately for each packet processor in a unit and for
each unit in a stack.
Cisco 500 Series Stackable Managed Switch Administration Guide
Quality of Service
Configuring QoS - General
.