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Cisco Systems OL-4266-08 manual Component Overview, Ingress LAN Port PFC QoS Features, 42-6

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Chapter 42 Configuring PFC QoS

Understanding How PFC QoS Works

Figure 42-4 PFC QoS Features and Component Overview

Port Trust
- CoS
- IP Prec	DSCP
- DSCP	map
- MPLS Exp

Identify traffic
based on match
criteria:
- ACL (L2, IP)
- DSCP	Final internal	Scheduler operates
- IP Prec	Final internal
	DSCP is
		on WRR, DWRR,
- MPLS Exp
	mapped to CoS
		SP
- Class-map

Ingress Port

PFC/DFC

C

l

Egress Port

Incoming

ToS

CoS

Q1

Q2

Scheduler

a
s
s
i
f			Policy				Result
i
i
c
a
t
i
o
n

DSCPCoS

rewrite

CoS determies queue selection

Q1		SP

Q2		Outgoing

		WRR


Q3		DWRR CoS set on

		trunk port
Q4		DSCP set
		for IP

Scheduling rules: WRR, PQ

Queueing based on CoS

Action - policy map

Trust - DSCP, IP Prec MPLS Exp

Mark - set internal

DSCP

Police - rate limit; mark; drop

Scheduler queue and threshold are configurable

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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, page 42-6

•PFC and DFC QoS Features, page 42-8

•PFC QoS Egress Port Features, page 42-12

Ingress LAN Port PFC QoS Features

These sections provide an overview of the ingress port QoS features:

•Flowchart of Ingress LAN Port PFC QoS Features, page 42-7

•Port Trust, page 42-8

•Ingress Congestion Avoidance, page 42-8

Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX

42-6	OL-4266-08

Image 6

Cisco Systems OL-4266-08 manual Component Overview, Ingress LAN Port PFC QoS Features, 42-6

Contents

A P T E R 42-1Port Types Supported by PFC QoS Overview42-2 PFC QoS Feature Processing Overview 42-32shows traffic flow and PFC QoS features with a PFC3 42-43shows traffic flow and PFC QoS features with a PFC2 42-5Ingress LAN Port PFC QoS Features Component Overview42-6 Flowchart of Ingress LAN Port PFC QoS Features 42-7Ingress Congestion Avoidance PFC and DFC QoS FeaturesPort Trust These sections describe PFCs and DFCs as they relate to QoSFeature Supported Policy Feature CardsPFC and DFC QoS Feature List and Flowchart Supported Distributed Forwarding Cards42-10 Ingress PFC QoSFinal Internal Dscp Value Internal Dscp ValuesInitial Internal Dscp Value 42-11Port-Based PFC QoS and VLAN-Based PFC QoS PFC QoS Egress Port FeaturesThese sections describe PFC QoS egress port features 42-12Flowchart of PFC QoS Egress LAN Port Features Egress CoS Values42-13 Egress PFC QoS Interfaces Egress Dscp Mutation with a PFC3Egress ToS Byte Egress ACL Support for Remarked DscpMarking on Egress OSM Ports 42-15Ingress Classification and Marking at Trusted Ports Understanding Classification and MarkingClassification and Marking at Untrusted Ingress Ports 42-16Ingress Classification and Marking at Trust Dscp Ports Classification and Marking at Ingress OSM PortsIngress Classification and Marking at Trust CoS LAN Ports 42-1742-18 Overview of Policers PolicersClassification and Marking on the Msfc These sections describe policersAggregate Policers 42-20Microflow Policers 42-21Understanding Port-Based Queue Types Ingress and Egress Buffers and Layer 2 CoS-Based Queues42-22 42-23 Ingress Queue Types 42-24Egress Queue Types 42-25Module to Queue Type Mappings Ingress Egress Queue Drop42-26 42-27 42-28 Feature Default Value PFC QoS Global SettingsFollowing global PFC QoS settings apply = CoS Egress CoS set from final internal Dscp valuesTransmit-Queue Limit s Default Values With PFC QoS EnabledReceive-Queue Limits 42-30Default Drop-Threshold Percentages and CoS Value Mappings Bandwidth Allocation Ratios42-31 1q2t Receive Queues 1q4t Receive Queues42-32 1p1q4t Receive Queues 1p1q0t Receive Queues42-33 1p1q8t Receive Queues 42-341q8t Receive Queues 42-352q8t Receive Queues 42-3611, 13, 15-17, 19, 21, 23 8q4t Receive QueuesStandard receive queue Threshold CoS Lowest priority 27, 29, 31, 33, 39, 41-4542-38 48-63 42-3942-40 8q8t Receive Queues 2q2t Transmit Queues42-41 1p2q2t Transmit Queues 42-421p3q8t Transmit Queues 42-431p7q4t Transmit Queues 42-4442-45 48-63 42-46Tail-drop 100% nonconfigurable 1p7q8t Transmit Queues42-47 1p3q1t Transmit Queues 42-48Default Values With PFC QoS Disabled 1p2q1t Transmit Queues42-49 General Guidelines 42-50PFC3 Guidelines Wrr-queue bandwidth except Gigabit Ethernet LAN ports42-51 PFC2 Guidelines 42-52Policy Map Class Command Restrictions Class Map Command RestrictionsPolicy Map Command Restrictions Supported Granularity for CIR and PIR Rate ValuesSupported Granularity for CIR and PIR Token Bucket Sizes 42-54IP Precedence and Dscp Values 42-55Command Purpose Enabling PFC QoS Globally42-56 Default Enables ignore port trust globally on the routerDisables ignore port trust globally on the router Enabling Ignore Port TrustConfiguring Dscp Transparency Enabling Queueing-Only Mode42-58 Enabling Microflow Policing of Bridged Traffic 42-59Enabling VLAN-Based PFC QoS on Layer 2 LAN Ports 42-60Enabling Egress ACL Support for Remarked Dscp Creating Named Aggregate Policers42-61 42-62 42-63 Configuring a PFC QoS Policy These sections describe PFC QoS policy configuration42-64 IPv4 Yes 100 to 1300 to 2000 to IPv6 Yes named PFC QoS Policy Configuration OverviewProtocol Numbered ACLs Extended ACLs Named ACLs Yes 800 to Yes 900 to Supported only with PFC2 MAC LayerConfiguring MAC ACLs Configuring Protocol-Independent MAC ACL Filtering42-66 Enabling VLAN-Based MAC QoS Filtering 42-67Configuring MAC ACLs 42-68Configuring ARP ACLs for QoS Filtering 42-69Configuring a Class Map Creating a Class Map42-70 Clears the ACL configuration from the class map Configuring Filtering in a Class MapOptional Configures the class map to filter using an ACL Class Map Filtering Guidelines and RestrictionsVerifying Class Map Configuration 42-72Creating a Policy Map Configuring a Policy MapPolicy Map Class Configuration Guidelines and Restrictions To create a policy map, perform this taskCreating a Policy Map Class and Configuring Filtering Configuring Policy Map Class Actions42-74 Configuring Policy Map Class Marking Configuring the Policy Map Class Trust State42-75 Configuring a Per-Interface Policer Configuring Policy Map Class PolicingUsing a Named Aggregate Policer 42-7642-77 42-78 Exits policy map class configuration mode Verifying Policy Map ConfigurationTo verify policy map configuration, perform this task Additional classes in the policy mapAttaches a policy map to the interface Attaching a Policy Map to an InterfaceTo attach a policy map to an interface, perform this task Removes the policy map from the interface42-81 Router# show policy-map interface fastethernet 5/36To configure a named Dscp mutation map, perform this task Configuring Egress Dscp Mutation on a PFC3Configuring Named Dscp Mutation Maps 42-82Removes the egress Dscp mutation map from Attaching an Egress Dscp Mutation Map to an InterfaceAttaches an egress Dscp mutation map to the interface 42-8342-84 Configuring Ingress CoS Mutation Maps 42-85Configuring Dscp Value Maps Mapping Received CoS Values to Internal Dscp Values42-86 Configuring Dscp Markdown Values Configures a Dscp markdown map42-87 42-88 Configures the internal Dscp to egress CoS map Mapping Internal Dscp Values to Egress CoS Values42-89 Reverts to the default trust state untrusted Configuring the Trust State of Ethernet LAN and OSM PortsConfigures the trust state of the port 42-90Configuring the Ingress LAN Port CoS Value 42-91Reverts to the default port CoS value Configuring Standard-Queue Drop Threshold PercentagesConfigures the ingress LAN port CoS value 42-92Configuring a Tail-Drop Receive Queue 42-93Configuring a WRED-Drop Transmit Queue Configuring a WRED-Drop and Tail-Drop Receive Queue42-94 Configuring a WRED-Drop and Tail-Drop Transmit Queue 42-95Configuring 1q4t/2q2t Tail-Drop Threshold Percentages 42-96Tail-drop thresholds Configures the receive- and transmit-queue tail-dropReverts to the default receive- and transmit-queue 42-97Configuring DSCP-Based Queue Mapping Mapping QoS Labels to Queues and Drop Thresholds42-98 Enabling DSCP-Based Queue Mapping Configuring Ingress DSCP-Based Queue MappingConfiguring the Port to Trust Dscp 42-99Maps Dscp values to the standard receive queue Reverts to the default mappingMapping Dscp Values to Standard Receive-Queue Thresholds 42-100Queueing interface command 42-101Mapping Dscp Values to Standard Transmit-Queue Thresholds Maps Dscp values to a standard transmit-queue42-102 Mapping Dscp Values to the Transmit Strict-Priority Queue 42-103Maps CoS values to the standard receive queue Configuring CoS-Based Queue MappingMapping CoS Values to Standard Receive-Queue Thresholds 42-104Mapping CoS Values to Standard Transmit-Queue Thresholds Maps CoS values to a standard transmit-queue threshold42-105 Mapping CoS Values to Strict-Priority Queues Maps CoS values to the receive and transmit42-106 Maps CoS values to a tail-drop threshold 42-107Allocating Bandwidth Between Standard Transmit Queues 42-10842-109 Sets the size ratio between the receive queues Setting the Receive-Queue Size RatioReverts to the default size ratio 42-110Configures the strict priority queue size Configuring the Transmit-Queue Size RatioConfigures the queue size ratio between transmit queues 42-111Sample Network Design Overview Access LayerDistribution and Core Interswitch Links 42-11242-113 Identify the SAP Traffic from the PC Dvlan Identify the Voice Signaling Traffic from an IP Phone VvlanIdentify the Voice Traffic from an IP Phone Vvlan 42-11442-115 Set dscp efAccepting the Traffic Priority Value on Interswitch Links 42-116Prioritizing Traffic on Interswitch Links 42-11742-118 CoS from DSCP-to-CoS map Output Queue Voice Strict Priority Voice signaling Queue 2, ThresholdTraffic Type 42-119Using Policers to Limit the Amount of Traffic from a PC Class map commands42-120 To monitor the policing operation, use these commands 42-121PFC QoS Glossary 42-12242-123 42-124