Cisco IOS™ 12.0 Quality of Service

Table of contents

1. Copyright
2. About This Book
   1. Acknowledgments
3. Introduction: Quality of Service Overview
   1. What Is QoS?
   2. About QoS Architecture
   3. Who Could Benefit from Using Cisco IOS QoS?
   4. Why Deploy Cisco IOS QoS?
   5. End-to-End QoS Models
      1. Best-Effort Service
      2. Integrated Service
      3. Differentiated Service
   6. Cisco's QoS Features
      1. Classification
         1. IP Precedence
         2. PBR
         3. CAR (Packet Classification)
         4. BGP Policy Propagation
      2. Congestion Management
         1. What Is Congestion in Networks?
         2. FIFO Queuing
         3. PQ
         4. CQ
         5. WFQ and VIP-Distributed WFQ
      3. Congestion Avoidance
         1. WRED
         2. VIP-Distributed WRED
         3. Policing and Shaping
            1. CAR Rate Limiting
            2. Shaping
         4. Signaling
         5. Link Efficiency Mechanisms
            1. Compressed Real-Time Protocol
            2. Link Fragmentation and Interleaving
      4. About the Cisco IOS 12.0 Reference Library
         1. Cisco IOS Reference Library Organization
         2. Books Available in the Cisco IOS 12.0 Reference Library
         3. Book Conventions
         4. Command Syntax Conventions
         5. Cisco Connection Online
      5. Using Cisco IOS Software
         1. Getting Help
            1. Example: How to Find Command Options
         2. Understanding Command Modes
            1. Summary of Main Command Modes
         3. Using the No and Default Forms of Commands
         4. Saving Configuration Changes
4. I. Classification
   1. 1. Classification Overview
      1. About IP Precedence
         1. How the IP Precedence Bits Are Used to Classify Packets
         2. Setting or Changing the IP Precedence Value
      2. Policy-Based Routing
         1. How It Works
         2. When Should You Use PBR?
      3. QoS Policy Propagation via Border Gateway Protocol
      4. Committed Access Rate
   2. 2. Configuring Policy-Based Routing
      1. PBR Configuration Task List
      2. Enable PBR
      3. Enable Fast-Switched PBR
      4. Enable Local PBR
      5. PBR Configuration Examples
         1. Equal Access Example
         2. Differing Next Hops Example
   3. 3. Configuring QoS Policy Propagation via Border Gateway Protocol
      1. QoS Policy Propagation via BGP Configuration Task List
         1. Overview of Tasks
         2. Configuration Task List
      2. Configure Policy Propagation Based on Community Lists
      3. Configure Policy Propagation Based on the AS Path Attribute
      4. Configure Policy Propagation Based on an Access List
      5. Monitor QoS Policy Propagation via BGP
      6. QoS Policy Propagation via BGP Configuration Examples
         1. Router A's Configuration
         2. Router B's Configuration
   4. 4. Configuring Committed Access Rate
      1. CAR Configuration Task List
      2. Configure CAR and DCAR for All IP Traffic
      3. Configure CAR and DCAR Policies
         1. IP Precedence or MAC Address
         2. IP Access List
      4. Configure a Class-Based DCAR Policy
      5. Monitor CAR and DCAR
      6. CAR and DCAR Configuration Examples
         1. Subrate IP Services Example
         2. Input and Output Rate Limiting on an Interface Example
         3. Rate Limiting in an IXP Example
         4. Rate Limiting by Access List Example
            1. Configuration Commands for Router LEFT
5. II. Congestion Management
   1. 5. Congestion Management Overview
      1. Why Use Congestion Management?
      2. Deciding Which Queuing Policy to Use
      3. First-In, First-Out Queuing
      4. Weighted Fair Queuing
         1. About WFQ
            1. WFQ and IP Precedence
            2. WFQ and Resource Reservation Protocol
            3. WFQ and Frame Relay
            4. Considerations
         2. VIP-Distributed WFQ
            1. Flow-Based VIP-Distributed WFQ
            2. Restrictions
            3. Drop Policy
      5. Custom Queuing
         1. How It Works
         2. Determining Byte Count Values for Queues
            1. How the Byte Count Is Used
            2. Determining the Byte Count
            3. Window Size
         3. Why Use CQ?
         4. Considerations
      6. Priority Queuing
         1. How It Works
         2. How Packets Are Classified for PQ
         3. Why Use PQ?
         4. Considerations
         5. Restrictions
   2. 6. Configuring Weighted Fair Queuing
      1. WFQ Configuration Task List
      2. Configure WFQ and DWFQ
      3. Monitor Fair Queuing
      4. Fair Queuing Configuration Examples
         1. WFQ Example
         2. DWFQ Example
   3. 7. Configuring Custom Queuing
      1. Custom Queuing Configuration Task List
      2. Define the Custom Queue List
      3. Specify the Maximum Size of the Custom Queues
      4. Assign Packets to Custom Queues
      5. Monitor Custom Queue Lists
      6. Custom Queuing Configuration Examples
         1. Define the Custom Queue List Example
         2. Specify Maximum Number of Packets Allowed in Each Custom Queue Example
         3. Specify Maximum Queue Size in Bytes Example
         4. Assign by Protocol Type Examples
         5. Assign by Interface Type Example
         6. Assign by Default Queue Example
   4. 8. Configuring Priority Queuing
      1. Priority Queuing Configuration Task List
      2. Define the Priority List
         1. Assign Packets to Priority Queues
         2. Specify the Maximum Size of the Priority Queues
      3. Assign the Priority List to an Interface
      4. Monitor Priority Queuing Lists
      5. Priority Queuing Configuration Examples
         1. Priority Queuing Based on Protocol Type Example
         2. Priority Queuing Based on Interface Example
         3. Specify the Maximum Size of the Priority Queue Example
         4. Assign Priority List to an Interface Example
         5. Priority Queuing Using Multiple Rules Example
6. III. Congestion Avoidance
   1. 9. Congestion Avoidance Overview
      1. Tail Drop
      2. Weighted Random Early Detection
         1. About RED
            1. How It Works
            2. Packet Drop Probability
            3. How TCP Handles Traffic Loss
            4. How the Router Interacts with TCP
         2. About WRED
            1. Why Use WRED?
            2. How It Works
            3. Average Queue Size
         3. VIP-Distributed WRED
            1. Why Use VIP-Distributed WRED?
            2. Restrictions
   2. 10. Configuring Weighted Random Early Detection
      1. WRED Configuration Task List
      2. Enable WRED
      3. Change WRED Parameters
      4. Monitor WRED and DWRED
      5. WRED and DWRED Configuration Examples
         1. WRED and DWRED Configuration Example
         2. Parameter-Setting DWRED Example
         3. Parameter-Setting WRED Example
7. IV. Policing and Shaping
   1. 11. Policing and Shaping Overview
      1. What Is a Token Bucket?
      2. Policing with CAR
         1. How It Works
            1. Matching Criteria
            2. Rate Limits
            3. Conform and Exceed Actions
            4. Multiple Rate Policies
         2. Restrictions
      3. Traffic Shaping
         1. About Traffic Shaping
            1. Why Use Traffic Shaping?
            2. Traffic Shaping and Rate of Transfer
            3. DE Bit
            4. Differences Between GTS and FRTS
            5. Traffic Shaping and Queuing
         2. GTS
         3. FRTS
            1. Derived Rates
            2. Restrictions
   2. 12. Configuring Generic Traffic Shaping
      1. GTS Configuration Task List
      2. Configure GTS
      3. Configure GTS for an Access List
      4. Configure Adaptive GTS for Frame Relay Networks
      5. Monitor the GTS Configuration
      6. GTS Configuration Examples
         1. Enable GTS on the Interface Example
         2. Constrained Access Rate Example
         3. Differing Controlled Rates through an IP Internet Example
         4. Frame Relay Adaptability to Congestion Example
         5. Accommodating Differing Access Speeds Example
   3. 13. Configuring Frame Relay and Frame Relay Traffic Shaping
      1. FRTS Configuration Task List
      2. Configure a Map Class
      3. Configure FRTS
         1. Virtual Circuits for Different Types of Traffic
         2. Traffic Shaping Tasks
         3. Enable FRTS on the Interface
            1. Understand the Frame Relay ForeSight Feature
            2. Congestion Notification Methods
            3. ForeSight Prerequisites
         4. Enable Enhanced Local Management Interface
         5. Specify a Traffic Shaping Map Class for the Interface
         6. Define a Map Class with Queuing and Traffic Shaping Parameters
         7. Define Access Lists
         8. Define Priority Queue Lists for the Map Class
         9. Define Custom Queue Lists for the Map Class
         10. Create a Broadcast Queue for an Interface
         11. Configure Discard Eligibility
         12. Configure DLCI Priority Levels
      4. Monitor the Frame Relay Connections
      5. FRTS Configuration Examples
         1. SVC Interface Example
         2. SVC Subinterface Example
         3. Traffic Shaping with Three Point-to-Point Subinterfaces Example
         4. Traffic Shaping with Router ForeSight Example
         5. ELMI Example
8. V. Signaling
   1. 14. Signaling Overview
      1. IP Precedence
      2. RSVP
      3. How It Works
   2. 15. Configuring RSVP
      1. RSVP Reservation Types
         1. Distinct Reservation
         2. Shared Reservation
      2. Planning for RSVP Configuration
         1. RSVP Implementation Considerations
            1. Frame Relay Internetwork Considerations
            2. ATM Internetwork Considerations
      3. Resource Reservation Protocol Configuration Task List
      4. Enable RSVP
      5. Enter Senders in the RSVP Database
      6. Enter Receivers in the RSVP Database
      7. Enter Multicast Addresses
      8. Control Which RSVP Neighbor Can Offer a Reservation
      9. Monitor RSVP
      10. RSVP Configuration for a Multicast Session Example
          1. Router A
          2. Router B
          3. Router C
9. VI. Link Efficiency Mechanisms
   1. 16. Link Efficiency Mechanisms Overview
      1. Link Fragmentation and Interleaving
         1. How It Works
      2. CRTP Header
         1. How It Works
         2. Why Use Compressed Real-Time Protocol Header?
   2. 17. Configuring Link Fragmentation and Interleaving for Multilink PPP
      1. Interleaving for Multilink PPP Configuration Task List
      2. Configure MLP Interleaving and Queuing for Real-Time Traffic
         1. Restrictions
         2. MLP Interleaving Configuration Tasks
      3. Monitor PPP and MLP Interfaces
      4. MLP Interleaving and Link Fragmentation Examples
   3. 18. Configuring Compressed Real-Time Protocol
      1. CRTP Configuration Task List
      2. Before You Configure CRTP
      3. Enable CRTP on a Serial Interface
      4. Enable CRTP with Frame Relay Encapsulation
      5. Change the Number of Header Compression Connections
      6. Display System and Network Statistics
      7. CRTP Configuration Examples
   4. 19. Quality of Service Commands
      1. access-list rate-limit
         1. Default
         2. Command Mode
         3. Usage Guidelines
         4. Examples
         5. Related Commands
      2. bgp-policy
         1. Default
         2. Command Mode
         3. Usage Guidelines
         4. Example
      3. custom-queue-list
         1. Default
         2. Command Mode
         3. Usage Guidelines
         4. Example
         5. Related Commands
      4. fair-queue
         1. Default
         2. Command Mode
         3. Usage Guidelines
         4. Examples
         5. Related Commands
      5. fair-queue (DWFQ)
         1. Syntax Description
         2. Default
         3. Command Mode
         4. Usage Guidelines
         5. Example
         6. Related Commands
      6. ip rsvp bandwidth
         1. Default
         2. Command Mode
         3. Usage Guidelines
         4. Example
         5. Related Commands
      7. ip rsvp neighbors
         1. Default
         2. Command Mode
         3. Usage Guidelines
         4. Example
         5. Related Commands
      8. ip rsvp reservation
         1. Default
         2. Command Mode
         3. Usage Guidelines
         4. Examples
         5. Related Commands
      9. ip rsvp sender
         1. Default
         2. Command Mode
         3. Usage Guidelines
         4. Example
         5. Related Commands
      10. ip rsvp udp-multicast
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Example
          5. Related Commands
      11. priority-group
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Example
          5. Related Commands
      12. priority-list default
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Example
          5. Related Commands
      13. priority-list interface
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Example
          5. Related Commands
      14. priority-list protocol
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Examples
          5. Related Commands
      15. priority-list queue-limit
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Example
          5. Related Commands
      16. queue-list default
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Example
          5. Related Commands
      17. queue-list interface
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Example
          5. Related Commands
      18. queue-list protocol
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Examples
          5. Related Commands
      19. queue-list queue byte-count
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Example
          5. Related Commands
      20. queue-list queue limit
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Example
          5. Related Commands
      21. random-detect
          1. Syntax Description
          2. Default
          3. Command Mode
          4. Usage Guidelines
          5. Example
          6. Related Commands
      22. random-detect exponential-weighting-constant
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Example
          5. Related Commands
      23. random-detect precedence
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Example
          5. Related Commands
      24. rate-limit
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Example
          5. Related Commands
      25. set ip precedence
          1. Syntax Description
          2. Default
          3. Command Mode
          4. Usage Guidelines
          5. Example
          6. Related Commands
      26. set ip qos-group
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Example
      27. show access-lists
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Sample Displays
          5. Related Commands
      28. show access-lists rate-limit
          1. Command Mode
          2. Usage Guidelines
          3. Sample Displays
          4. Related Commands
      29. show interfaces
          1. Command Mode
          2. Usage Guidelines
          3. Sample Display for DWFQ
          4. Sample Display for DWRED
      30. show interfaces fair-queue
          1. Command Mode
          2. Usage Guidelines
          3. Sample Display
      31. show interfaces random-detect
          1. Command Mode
          2. Usage Guidelines
          3. Sample Display
          4. Related Commands
      32. show interfaces rate-limit
          1. Command Mode
          2. Usage Guidelines
          3. Sample Display
          4. Related Commands
      33. show ip cef
          1. Command Mode
          2. Usage Guidelines
          3. Sample Display
      34. show ip interface
          1. Command Mode
          2. Usage Guidelines
          3. Sample Display
      35. show ip rsvp installed
          1. Command Mode
          2. Usage Guidelines
          3. Sample Display
      36. show ip rsvp interface
          1. Command Mode
          2. Usage Guidelines
          3. Sample Display
      37. show ip rsvp neighbor
          1. Command Mode
          2. Usage Guidelines
          3. Sample Display
      38. show ip rsvp request
          1. Command Mode
          2. Usage Guidelines
          3. Sample Display
      39. show ip rsvp reservation
          1. Command Mode
          2. Usage Guidelines
          3. Sample Display
      40. show ip rsvp sender
          1. Command Mode
          2. Usage Guidelines
          3. Sample Display
      41. show queue
          1. Command Mode
          2. Usage Guidelines
          3. Sample Display
      42. show queuing
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Sample Displays
          5. Related Commands
      43. show tech-support rsvp
          1. Syntax Description
          2. Default
          3. Command Mode
          4. Usage Guidelines
      44. show traffic-shape
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Sample Display
          5. Related Commands
      45. show traffic-shape statistics
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Sample Display
          5. Related Commands
      46. traffic-shape adaptive
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Example
          5. Related Commands
      47. traffic-shape fecn-adapt
          1. Syntax Description
          2. Default
          3. Command Mode
          4. Usage Guidelines
          5. Example
          6. Related Commands
      48. traffic-shape group
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Example
          5. Related Commands
      49. traffic-shape rate
          1. Default
          2. Command Mode
          3. Usage Guidelines
          4. Example
          5. Related Commands