Component Overview - Cisco WS-SUP32-GE-3B - Supervisor Engine 32 Software Configuration Manual

Chapter 38 Configuring PFC QoS
Figure 38-3 PFC QoS Features and Component Overview
Port Trust
- CoS
- IP Prec
- DSCP
- MPLS Exp
Ingress Port
Incoming
Q1
ToS
CoS
Q2
Scheduling rules: WRR, PQ
Queueing based on CoS

Component Overview

These sections provide more detail about the role of the following components in PFC QoS decisions
and processes:
•
•
•
Ingress LAN Port PFC QoS Features
These sections provide an overview of the ingress port QoS features:
•
•
•
OL-11439-03
DSCP
map
Scheduler
Ingress LAN Port PFC QoS Features, page 38-5
PFC QoS Features, page 38-7
PFC QoS Egress Port Features, page 38-11
Flowchart of Ingress LAN Port PFC QoS Features, page 38-6
Port Trust, page 38-7
Ingress Congestion Avoidance, page 38-7
Catalyst Supervisor Engine 32 PISA Cisco IOS Software Configuration Guide, Release 12.2ZY
Identify traffic
based on match
criteria:
- ACL (L2, IP)
- DSCP
Final internal
- IP Prec
DSCP is
- MPLS Exp
mapped to CoS
- Class-map
PFC/DFC
C
l
a
s
s
i
f
Policy Result
i
c
a
t
i
o
n
Action - policy map
Trust - DSCP, IP Prec
MPLS Exp
Mark - set internal
DSCP
Police - rate limit; mark; drop
Understanding How PFC QoS Works
Scheduler operates
on WRR, DWRR,
SP
Egress Port
Q1 SP
Q2
DSCP CoS
WRR
rewrite
Q3 DWRR
CoS determies
queue selection
Q4
Scheduler queue
and threshold are
configurable
Outgoing
CoS set on
trunk port
DSCP set
for IP
38-5