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Chapter 3 QoS in an AVVID-Enabled Campus Network
Selecting an Access-Layer Switch
Note
From a configuration perspective, the Catalyst 2948G, the Catalyst 2980G, and the Catalyst 4000 family
of switches are the same. Therefore, the configuration of only one, the Catalyst 4000, is shown in this
section.
Catalyst 4000 with Supervisor III
The Catalyst 4000 Supervisor III introduces many enhanced QoS features to the Catalyst 4000, including
four queues per port with a configurable priority queue.
shows a general model for the Catalyst 4000 with Supervisor III as an access device (as
illustrated in the QoS configurations discussed in this chapter).
Figure 3-8
General Model for Catalyst 4000 with Supervisor III QoS Configurations
This section presents suggested configurations for port scheduling and queuing on the Catalyst 4000
with Supervisor III. In general:
·
The recommended configuration for the receive interface is FIFO--one standard FIFO queue.
·
The recommended configuration for the transmit interface is 1P3Q1T--one priority queue (when
configured) and three queues with a single threshold. Scheduling is done on a WRR basis.
Admission to the queues is based on IP DSCP value and is user configurable.
Si
Si
Si
IP
VVID=111
VLAN=11
Core
Distribution
Access
Catalyst
6500
Catalyst 4000
74699