Cisco Systems EA6500 Manual De Usuario

QoS selects network traffic (both unicast and multicast), prioritizes it according to its relative 
importance, and uses congestion avoidance to provide priority-indexed treatment; QoS can also limit the 
bandwidth used by network traffic. QoS makes network performance more predictable and bandwidth 
utilization more effective.

On the Catalyst 6500 series switches, queue architecture and QoS queueing features such as 
Weighted-Round Robin (WRR) and Weighted Random Early Detection (WRED) are implemented with 
a fixed configuration in Application Specific Integrated Circuits (ASICs). The queueing architecture 
cannot be reconfigured. For more information, see the 

 and the 

These sections describe PFC QoS:

With Release 12.1(11a)E and later, PFC QoS supports both LAN ports and optical services module 
(OSM) ports:

LAN ports are Ethernet ports on Ethernet switching modules, except for the 4-port Gigabit Ethernet 
WAN (GBIC) module (OSM-4GE-WAN). Except for the OSM-4GE-WAN module, OSMs have four 
Ethernet LAN ports in addition to WAN ports. With earlier releases, PFC QoS supports only LAN 
ports.

OSM ports are the WAN ports on OSMs. The PFC provides ingress QoS for traffic from OSM ports. 
For more information, see the following sections:

Refer to the following publication for information about additional OSM QoS features: