Enterprise QoS Solution Reference Network Design Guide

Catalyst 6500 PFC2/PFC3—QoS Considerations and Design
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Enterprise QoS Solution Reference Network Design Guide
Chapter 2 Campus QoS Design
AutoQoS VoIP and conditional trust have been committed for future releases of Catalyst 6500 IOS. The
QoS design recommendations for a Catalyst 6500 switch at the access layer are summarized in
Figure 2-22; the corresponding recommendations for Catalyst 6500s deployed in the distribution or core
layers is shown in Figure 2-23.
Figure 2-22 Access Layer (CatOS) Catalyst 6500 QoS Design Options
Enable QoS
Globally
Figure 2-23 Distribution and/or Core Layer (IOS) Catalyst 6500 QoS Design
Distribution Layer:
Enable QoS
Globally
Core Layer:
Enable QoS
Globally
Access-Edges
Trusted-Endpoint
Model
AutoQoS–VoIP
Model
PC + SoftPhone +
Scavenger Model
Untrusted Server +
Scavenger Model
IP Phone + PC +
Scavenger (Basic) Model
IP Phone + PC +
Scavenger (Adv) Model
Trust-DSCP
Trust-DSCP
Uplinks from Access Layer Only
Optional (PFC3 Only):
Per-User Microflow
Policing
Interswitch Links
Interswitch Links
Trust-DSCP
Uplinks to
Distribution Layer
Interface-Group
Line Card-Dependent
Queuing + Dropping
Interface-Group
Line Card-Dependent
Queuing + Dropping
Globally-Defined
Linecard-Dependant
Queuing + Dropping
Note To narrow the scope of our discussion to the most current and relevant versions of the Catalyst 6500
switch-family, only the Catalyst 6500 with Supervisor 2 (PFC2) and Supervisor 720 (PFC3) be examined
in this design chapter. For discussions of older versions of Catalyst 6000/6500s (such as Supervisor 1,
1a with/without a PFC), refer to the Cisco Press book, Cisco Catalyst QoS: Quality of Service in Campus
Networks, by Mike Flannagan, Richard Froom and Kevin Turek.
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