Implementing Cisco Quality of Service 2.3 (QOS 2.3)

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About this Course

Implementing Cisco Quality of Service (QoS) v2.3 provides learners with in-depth knowledge of quality of service (QoS) requirements, conceptual models such as Best Effort, Integrated Services (IntServ) and Differentiated Services (DiffServ), and the implementation of QoS on Cisco IOS platforms. This five-day course covers the theory of QoS, design issues, and configuration of various QoS mechanisms to facilitate the creation of effective administrative policies providing QoS. Case studies and lab exercises included in the course help learners to apply the concepts mastered in individual modules to real-life scenarios. The course also gives learners design and usage rules for various advanced QoS features and the integration of QoS with underlying Layer 2 QoS mechanisms. This gives learners the opportunity to design and implement efficient, optimal, and trouble-free multiservice networks. Upon completion of this course, the learner will be able to identify, describe, and correctly implement the appropriate QoS mechanisms that are required to create an effective administrative policy providing QoS. This course helps students prepare for QoS Exam #642-642.

Audience Profile

  • Pre- and post-sales technical engineers responsible for designing, implementing, or troubleshooting networks
  • Network architects responsible for designing multiservice networks to carry voice, video, and data traffic in an enterprise or service provider environment
  • CCIP & CCVP candidates

At Course Completion

After completing this course, students will be able to:

  • Explain the need to implement QoS and explain methods for implementing and managing QoS.
  • Identify and describe different models used for ensuring QoS in a network and explain key QoS mechanisms used to implement the models.
  • Explain the use of MQC and AutoQoS to implement QoS on the network.
  • Classify and mark network traffic to implement a policy defining QoS requirements.
  • Use Cisco QoS queuing mechanisms to manage network congestion.
  • Use Cisco QoS congestion avoidance mechanisms to reduce the effects of congestion on the network.
  • Use Cisco QoS traffic policing and traffic shaping mechanisms to effectively limit the rate of network traffic
  • Use Cisco link efficiency mechanisms to improve the bandwidth efficiency of a low-speed WAN links.
  • Select the most appropriate QoS mechanisms for providing QoS using Cisco “best practices” in service provider and enterprise networks.


To fully benefit from this course, students should have the following prerequisite skills and knowledge:

  • Completion of ICND1 and ICND2 or Cisco CCNA certification
  • BGP or equivalent is recommended because some BGP background is assumed

Course Outline:

Module 1: Introduction to QoS 2.3

Lesson 1: Understanding the Need for QoS

  •  Converged Networks
  • Converged Networks Quality Issues
  • Available Bandwidth
  • End-to-End Delay
  • Packet Loss

Lesson 2: Understanding QoS

  • Qos Defined
  • QoS for Converged Networks
  • QoS Requirements
  • QoS Traffic Classes
  • QoS Policy

Lesson 3: Implementing QoS

  •  Methods for Implementing QoS Policy
  • Legacy CLI
  • Modular QoS CLI
  • AutoQoS VoIP and Enterprise
  • QoS Implementation Methods Compared
  • QoS Policy Manager
  • Network MIBs for Monitoring QoS
  • MIBs for Managing QoS

Module 2: The Building Blocks of QoS

Lesson 1: Identifying Models for Implementing QoS

  • QoS Models
  • Best-Effort Model
  • IntServ Model
  • DiffServ Model

Lesson 2: Understanding the Integrated Services Model

  • Integrated Services Model
  • RSVP Components
  • RSVP Interface Bandwidth Queuing
  • Enabling RSVP on an Interface
  • IntServ and DiffServ Integration

Lesson 3: Understanding the Differentiated Services Model

  •  Differentiated Services Model
  • DSCP Encoding
  • Per-Hop Behaviors
  • Backward Compatibility Using the Class Selector

Lesson 4: Identifying QoS MEchanisms

  • QoS Mechanisms
  • Classification
  • Marking
  • Congestion Management
  • Congestion Avoidance
  • Policing and Shaping
  • Link Efficiency Mechanisms
  • Link Fragmentation and Interleaving
  • Applying QoS to Input and Output Interfaces

Lesson 5: Understanding QoS in the Life of a Packet

  •  QoS and Packets
  • Life of a High-Priority (VoIP) Packet
  • Life of a Low-Priority (FTP) Packet

Module 3: Introduction to Modular QoS CLI and AutoQoS

Lesson 1: Introducing Modular QoS CLI

  • Modular QoS CLI
  • Modular QoS CLI Components
  • Class Maps
  • Configuring and Monitoring Class Maps
  • Policy Maps
  • Configuring and Monitoring Policy Maps
  • Service Policy
  • Attaching Service Policies to Interfaces

Lesson 2: Introducing Cisco AutoQoS VoIP

  • Cisco AutoQoS VoIP
  • AutoQoS VoIp: Router Platforms
  • AutoQoS VoIP: Switch Platforms
  • Configuring AutoQoS VoIP
  • Monitoring AutoQoS VoIP
  • Automation with Cisco AutoQoS

Lesson 3: Introducing Cisco AutoQoS Enterprise

  • Cisco AutoQoS Enterprise
  • AutoQoS Enterprise Router Platforms
  • Configuring AutoQoS Enterprise
  • Monitoring AutoQoS Enterprise

Module 4: Classification and Marking

Lesson 1: Understanding Classification and Marking

  • Classification
  • Classification and Marking at the Data-Link Layer
  • Classification and Marking at the Network Layer
  • Marking
  • Mapping CoS to Network Layer QoS
  • QoS Service Defined
  • Implementing a QoS Policy Using a QoS Service Class
  • Trust Boundaries

Lesson 2: Using UQC for Classification

  • MQC Classification Options
  • Configuring Classification with MQC
  • Configuring Classification Using Input Interface
  • Configuring Classification Using CoS
  • Configuring Classification Using Access Lists
  • Configuring Classification Using IP Precedence
  • Configuring Classification Using DSCP
  • Configuring Classification Using a UDP Port Range
  • Monitoring Class Maps

Lesson 3: Using MQC for Class-Based Marking

  • Class-Based Marking Overview
  • MQC Marking Options
  • Configuring Class-Based Marking
  • Configuring CoS Marking
  •  Configuring IP Precedence Marking
  • Configuring IP DSCP Marking
  • Monitoring Class-Based Marking

Lesson 4: Using NBAR for Classification

  •  Network-Based Application Recognition
  • NBAR Application Support
  • Packet Description Language Module
  • Protocol Discovery
  • Configuring and Monitoring Protocol Discovery
  • Configuring NBAR for Static Protocols
  • Configuring NBAR for Stateful Protocols

Lesson 5: Configuring QoS Preclassify

  • Implementing QoS with Preclassify
  • QoS Preclassify Applications
  • QoS Preclassify Deployment Options
  • Configuring QoS Preclassify
  • Monitoring QoS Preclassify

Lesson 6: Configuring QoS Policy Propagation Through BGP

  •  QoS Policy Propagation Through BGP
  • QoS and BGP Interaction
  • Cisco Express Forwarding
  • QPPB Configuration Tasks
  • Configuring QPPB

Lesson 7: Configuring LAN Classification and Marking

  • LAN-Based Classification and Marking
  • QoS Trust Boundaries
  • LAN Classification and Marking Platforms
  • Configuring LAN-Based Classification and Marking
  • Monitoring LAN-Based Classification and Marking

Module 5: Congestion Management

Lesson 1: Introducing Queuing

  • Congestion and Queuing
  • Queuing Algorithms
  • First In First Out
  • Priority Queuing
  • Round Robin
  • Weighted Round Robin
  • Deficit Round Robin

Lesson 2: Understanding Queuing Implementations

  • Queuing Components
  • Hardware Queue (TxQ) Size
  • Congestion on Software Interfaces
  • Queuing Implementations in Cisco IOS

Lesson 3: Configuring FIFO and WFQ

  • FIFO Queuing
  • Weighted Fair Queuing
  • WFQ Classification
  • WFQ Insertion and Drop Policy
  •  WFQ Scheduling
  • Benefits and Drawbacks of WFQ
  • Configuring WFQ
  • Monitoring WFQ

Lesson 4: Configuring CBWFQ and LLQ

  • CBWFQ and LLQ
  • Class-Based Weighted Fair Queuing
  • CBWFQ Architecture
  • CBWFQ Benefits
  • Configuring and Monitoring CBWFQ
  • Low-Latency Queuing
  • LLQ Architecture
  • LLQ Benefits
  • Configuring and Monitoring LLQ

Lesson 5: Configuring LAN Congestion Management

  • Queuing on Catalyst Switches
  • Weighted Round Robin
  • Configuring CoS-to-Queue Mappings for PQ on Catalyst 2950 Switches
  •  Configuring WRR on Catalyst 2950
  • Monitoring Queuing on Catalyst 2950 Switches

Module 6: Congestion Avoidance

Lesson 1: Introducing Congestion Avoidance

  •  Behavior of TCP Senders and Receivers
  • Congestion and TCP
  • Managing Interface Congestion with Tail Drop
  • Tail Drop Limitations

Lesson 2: Introducing RED

  • Random Early Detection
  • RED Profiles
  • RED Modes
  • TCP Traffic Before and After RED
  • Applying Congestion Avoidance

Lesson 3: Configuring Class-Based Weighted RED

  • Weighted Random Early Detection
  • WRED Profiles
  • Configuring CB-WRED
  • Configuring DSCP-Based CB-WRED
  • Monitoring CB-WRED

Lesson 4: Configuring Explicit Congestion Notification

  • Explicit Congestion Notification
  • ECN Field Defined
  • ECN and WRED
  • Configuring ECN-Enabled WRED
  • Monitoring ECN-Enabled WRED

Module 7: Traffic Policing and Shaping

Lesson 1: Understanding Traffic Policing and Shaping

  • Traffic Policing and Shaping Overview
  • Why Use Traffic Conditioners?
  • Policing vs. Shaping
  • Measuring Traffic Rates
  • Single Token Bucket Class-Based Policing
  • Dual Token Bucket Class-Based Policing
  • Dual-Rate Token Bucket Class-Based Policing
  • Class-Based Traffic Shaping
  • Cisco IOS Traffic Policing and Shaping Mechanisms
  • Applying Traffic Conditioners

Lesson 2: Configuring Class-Based Policing

  • Class-Based Policing Overview
  • Configuring Single-Rate Class-Based Policing
  • Configuring Dual-Rate Class-Based Policing
  • Configuring Percentage-Based Class-Based Policing
  • Monitoring Class-Based Policing

Lesson 3: Configuring Class-Based Shaping

  • Class-Based Shaping Overview
  • Traffic Shaping Methods
  • Configuring Class-Based Shaping
  • Monitoring Class-Based Shaping

Lesson 4: Configuring Class-Based Shaping on Frame Relay Interfaces

  • Frame Relay Refresher
  • Frame Relay Congestion Control
  • Frame Relay Congestion Adaptation
  • FECN-to-BECN Propagation
  • Configuring Frame Relay Adaptive Class-Based Shaping
  • Monitoring MQC-Based Frame Relay Traffic Shaping
  • MQC-Based Frame Relay Traffic Shaping Example on Multipoint Main Interface

Lesson 5: Frame Relay Voice-Adaptive Traffic Shaping and Fragmentation

  • Frame Rely Voice-Adaptive Traffic Shaping and Fragmentation
  • Benefits in Deploying FR-VATS
  • Prerequisites for Deploying FR-VATS
  • Supported Platforms
  • Frame Relay Voice-Adaptive Traffic Shaping and Fragmentation Operation
  • Configuring the Frame Relay Voice-Adaptive Feature
  • Monitoring the Frame Relay Voice-Adaptive Feature

Module 8: Link Efficiency Mechanisms

Lesson 1: Understanding Link Efficiency Mechanisms

  • Link Efficiency Mechanisms Overview
  • L2 Payload Compression
  • Header Compression
  • Large Packets “Freeze Out” Voice on Slow WAN Links
  • Link Fragmentation and Interleaving
  • Applying Link Efficiency Mechanisms

Lesson 2: Configuring Class-Based Header Compression

  • Header Compression Overview
  • Class-Based TCP Header Compression
  • Class-Based RTP Header Compression
  • Configuring Class-Based Header Compression
  • Monitoring Class-Based Header Compression

Lesson 3: Configuring Link Fragmentation and Interleaving

  • Fragmentation Options
  • Serialization Delay and Fragment Sizing
  • Configuring MLP with Interleaving
  • Monitoring MLP with Interleaving
  • FRF.12 Frame Relay Fragmentation
  • Configuring FRF.12 Frame Relay Fragmentation
  • Monitoring FRF.12 Frame Relay Fragmentation

Module 9: QoS Best Practices

Lesson 1: Understanding Traffic Classification Best Practices

  • QoS Best Practices
  • Voice, Video, and Data QoS Requirements
  • QoS Requirements Summary
  • Traffic Classification
  • Enterprise to Service Provider QoS Class Mapping

Lesson 2: Deploying End-to-End QoS

  • QoS Service Level Agreements
  • Deploying End-to-End Qos
  • Enterprise Campus QoS Implementations
  • WAN Edge (CE/PE) QoS Implementations
  • Service Provider Backbone QoS Implementations

Lesson 3: Providing QoS for Security

  • Business Security Threat
  • Increasing Occurrence of Network Attacks
  • The Impact of an Internet Work Attack
  • QoS Tools and Tactics for Security
  • Control Plane Policing
  • Data Plane Policing
  • NBAR Known-Worm Policing
  • Integrating Security Through QoS