The official self-study test preparation guide for the Cisco DQOS 9E0-601 and QOS 642-641 examsThis official study guide helps you master all the topics on the DQOS exam, including:QoS concepts, tools, and architecturesClassification and marking concepts and toolsQueuing in Cisco routers and configuration of queuing toolsTraffic policing and shaping in Cisco routersConfiguration of congestion avoidance toolsConfiguration of link-efficiency toolsCall admission control (CAC) tools for voice and video connectionsCisco QoS management toolsQoS design processesQoS on LAN switchesThe Cisco IP Telephony Support, Design, and Operations Specialist focused certifications validate proficiency in designing, installing, and supporting a multiservice network solution. A solid understanding of quality-of-service (QoS) features and implementation is essential for all of the Cisco IP Telephony focused certifications and is also a core component of the CCIP(tm) certification.
Author(s): Wendell Odom, Michael Cavanaugh
Series: IP Telephony Self-Study
Edition: Bk&CD-Rom
Publisher: Cisco Press
Year: 2003
Language: English
Commentary: 9033
Pages: 936
“Do I Know This Already?” Quiz......Page 39
QoS: Tuning Bandwidth, Delay, Jitter, and Loss Questions......Page 40
Traffic Characteristics of Voice, Video, and Data Questions......Page 41
Foundation Topics......Page 42
QoS: Tuning Bandwidth, Delay, Jitter, and Loss......Page 43
Bandwidth......Page 45
QoS Tools That Affect Bandwidth......Page 47
Delay......Page 49
Serialization Delay......Page 50
Propagation Delay......Page 52
Queuing Delay......Page 54
Shaping Delay......Page 56
Network Delay......Page 58
Delay Summary......Page 59
QoS Tools That Affect Delay......Page 60
Jitter......Page 63
QoS Tools That Affect Jitter......Page 64
QoS Tools That Affect Loss......Page 65
Traffic Characteristics of Voice, Video, and Data......Page 68
Voice Basics......Page 69
Voice Bandwidth Considerations......Page 72
Voice Delay Considerations......Page 75
Voice Jitter Considerations......Page 84
Voice Loss Considerations......Page 85
Video Basics......Page 88
Video Bandwidth Considerations......Page 90
Video Delay Considerations......Page 91
Video Jitter Considerations......Page 92
Data Traffic Characteristics......Page 93
IP Data Basics......Page 94
Data Bandwidth Considerations......Page 99
Data Jitter Considerations......Page 100
Data Loss Considerations......Page 101
Comparing Voice, Video, and Data: Summary......Page 102
Foundation Summary......Page 103
Q&A......Page 115
“Do I Know This Already?” Quiz......Page 119
QoS Tools Questions......Page 120
Integrated Services Questions......Page 121
Classification and Marking......Page 122
Classification and Marking Tools......Page 125
Queuing......Page 126
Queuing Tools......Page 127
Shaping and Policing......Page 129
Shaping and Policing Tools......Page 131
Congestion Avoidance......Page 132
Link Efficiency......Page 133
Link-Efficiency Tools: Summary......Page 135
Call Admission Control and RSVP......Page 136
CAC Tools......Page 137
Management Tools......Page 138
Summary......Page 139
The Good-Old Common Sense QoS Model......Page 140
GOCS Flow-Based QoS......Page 141
GOCS Class-Based QoS......Page 144
Classification and Marking at the Edge......Page 145
DiffServ Specifications and Terminology......Page 150
DiffServ Per-Hop Behaviors......Page 155
The Class Selector PHB and DSCP Values......Page 157
The Assured Forwarding PHB and DSCP Values......Page 161
The Expedited Forwarding PHB and DSCP Values......Page 164
DiffServ Classifiers and Traffic Conditioners......Page 165
The Integrated Services QoS Model......Page 169
Foundation Summary......Page 173
Q&A......Page 188
“Do I Know This Already?” Quiz Questions......Page 191
Classification and Marking Concepts Questions......Page 192
CAR, PBR, and CB Marking Questions......Page 193
Classification......Page 194
Marking......Page 198
IP Header QoS Fields: Precedence and DSCP......Page 199
LAN Class of Service (CoS)......Page 202
Summary of Marking Fields......Page 204
Classification and Marking Design Choices......Page 206
Class-Based Marking (CB Marking)......Page 211
Network-Based Application Recognition (NBAR)......Page 221
CB Marking show Commands......Page 225
Committed Access Rate (CAR)......Page 229
CAR Marking Summary......Page 236
Policy-Based Routing (PBR)......Page 237
VoIP Dial Peer......Page 243
Summary of Classification and Marking QoS Features......Page 250
Foundation Summary......Page 253
Q&A......Page 265
“Do I Know This Already?” Quiz......Page 269
WFQ and IP RTP Priority Questions......Page 270
Comparing Queuing Options Questions......Page 271
Queuing Concepts......Page 272
Output Queues, TX Rings, and TX Queues......Page 275
Queuing on Interfaces Versus Subinterfaces and Virtual Circuits (VCs)......Page 281
Queuing Tools......Page 284
FIFO Queuing......Page 285
Priority Queuing......Page 287
Custom Queuing......Page 290
Weighted Fair Queuing (WFQ)......Page 293
WFQ Classification......Page 294
WFQ Scheduler: The Net Effect......Page 295
WFQ Scheduling: The Process......Page 296
WFQ Drop Policy, Number of Queues, and Queue Lengths......Page 300
WFQ Configuration......Page 302
WFQ Summary......Page 307
Class-Based WFQ (CBWFQ)......Page 308
CBWFQ Configuration......Page 311
CBWFQ Summary......Page 323
Low Latency Queuing (LLQ)......Page 324
LLQ Configuration......Page 326
LLQ with More Than One Priority Queue......Page 331
IP RTP Priority......Page 332
IP RTP Priority Configuration......Page 333
Summary of Queuing Tool Features......Page 335
Foundation Summary......Page 337
Priority Queuing and Custom Queuing......Page 349
CBWFQ, LLQ, IP RTP Priority......Page 350
Comparing Queuing Tool Options......Page 352
“Do I Know This Already?” Quiz......Page 355
Policing with CAR and CB Policer Questions......Page 356
Shaping with FRTS, GTS, DTS, and CB Shaping......Page 357
Traffic-Policing and Traffic-Shaping Concepts......Page 358
When and Where to Use Shaping and Policing......Page 359
Policing—When and Where?......Page 360
Traffic Shaping—When and Where?......Page 363
How Shaping Works......Page 366
Traffic Shaping, Excess Burst, and Token Buckets......Page 371
Traffic-Shaping Adaption......Page 373
Where to Shape: Interfaces, Subinterfaces, and VCs......Page 374
Queuing and Traffic Shaping......Page 376
CAR Internals......Page 379
CB Policing Internals......Page 384
Policing, but Not Discarding......Page 386
Generic Traffic-Shaping Configuration......Page 387
Class-Based Shaping Configuration......Page 393
Distributed Traffic Shaping (DTS) Configuration......Page 405
Frame Relay Traffic Shaping (FRTS) Configuration......Page 406
Traffic-Policing Tools......Page 424
Class-Based Policing Configuration......Page 426
Committed Access Rate (CAR) Configuration......Page 434
Foundation Summary......Page 441
Shaping and Policing Concepts......Page 457
Traffic Shaping......Page 458
Traffic-Policing Tools......Page 459
“Do I Know This Already?” Quiz......Page 461
WRED Questions......Page 462
FRED Questions......Page 463
TCP and UDP Reactions to Packet Loss......Page 464
Tail Drop, Global Synchronization, and TCP Starvation......Page 468
Random Early Detection (RED)......Page 470
How WRED Weights Packets......Page 473
WRED and Queuing......Page 477
WRED Configuration......Page 479
WRED Summary......Page 491
Flow-Based WRED (FRED)......Page 492
FRED Configuration......Page 495
Foundation Summary......Page 502
Congestion-Avoidance Concepts and Random Early Detection (RED)......Page 511
Flow-Based WRED (FRED)......Page 512
Link-Efficiency Tools......Page 515
Compression Questions......Page 516
Link Fragmentation and Interleave Questions......Page 517
Payload and Header Compression......Page 518
Payload Compression......Page 520
Header Compression......Page 521
Payload Compression Configuration......Page 522
TCP and RTP Header Compression Configuration......Page 526
Link Fragmentation and Interleaving......Page 530
Multilink PPP LFI......Page 533
Maximum Serialization Delay and Optimum Fragment Sizes......Page 534
Frame Relay LFI Using FRF.12......Page 535
Choosing Fragment Sizes for Frame Relay......Page 539
Fragmentation with More Than One VC on a Single Access Link......Page 540
Multilink PPP Interleaving Configuration......Page 542
Frame Relay Fragmentation Configuration......Page 551
FRF.11-C and FRF.12 Comparison......Page 561
Foundation Summary......Page 564
Compression Tools......Page 572
LFI Tools......Page 573
Call Admission Controland QoSSignaling......Page 577
“Do I Know This Already?” Quiz......Page 578
Call Admission Control Overview......Page 580
Call Rerouting Alternatives......Page 581
Bandwidth Engineering......Page 582
CAC Mechanisms......Page 588
CAC Mechanism Evaluation Criteria......Page 589
Physical DS0 Limitation......Page 590
Max-Connections......Page 592
Voice over Frame Relay—Voice Bandwidth......Page 599
Trunk Conditioning......Page 602
Local Voice Busyout......Page 605
Measurement-Based Voice CAC......Page 607
SAA Service......Page 608
Advanced Voice Busyout......Page 609
PSTN Fallback......Page 611
IP Destination Caching......Page 612
PSTN Fallback Configuration......Page 614
PSTN Fallback Scalability......Page 617
PSTN Fallback Summary......Page 618
Resource-Based CAC......Page 620
Gateway Calculation of Resources......Page 621
RAI in Service Provider Networks......Page 622
RAI in Enterprise Networks......Page 624
RAI Configuration......Page 625
RAI Platform Support......Page 626
Location-Based CAC Operation......Page 627
Locations and Regions......Page 628
Calculation of Resources......Page 630
Location-Based CAC Summary......Page 631
Single-Zone Topology......Page 632
Multizone Topology......Page 633
Gatekeeper in CallManager Networks......Page 637
Zone Bandwidth Calculation......Page 638
Zone Bandwidth Configuration......Page 640
Gatekeeper Zone Bandwidth Summary......Page 641
Integrated Services / Resource Reservation Protocol......Page 642
RSVP Levels of Service......Page 643
RSVP Operation......Page 644
RSVP/H.323 Synchronization......Page 647
RSVP Synchronization Configuration......Page 648
Classification for Voice Packets into LLQ......Page 651
Bandwidth per Codec......Page 652
Subnet Bandwidth Management......Page 653
RSVP Configuration......Page 654
Monitoring and Troubleshooting RSVP......Page 657
RSVP CAC Summary......Page 660
Foundation Summary......Page 662
Local-Based CAC......Page 690
Resources-Based CAC......Page 691
“Do I Know This Already?” Quiz......Page 693
QoS Management Tools Questions......Page 694
QoS Design Questions......Page 695
QoS Device Manager......Page 696
QoS Policy Manager......Page 698
Service Assurance Agent......Page 700
Service Management Solution......Page 702
QoS Design for the Cisco QoS Exams......Page 704
Four-Step QoS Design Process......Page 705
Step 2: Characterize the Network......Page 706
Step 3: Implement the Policy......Page 707
Step 4: Monitor the Network......Page 708
Voice and Video: Bandwidth, Delay, Jitter, and Loss Requirements......Page 709
Voice and Video QoS Design Recommendations......Page 712
Foundation Summary......Page 715
QoS Management......Page 720
QoS Design......Page 721
“Do I Know This Already?” Quiz......Page 723
Buffer Overflow (Overrun)......Page 726
Marking and Classification......Page 727
Layer 3-to-Layer 2 Classification Mapping......Page 729
Layer 2 Queues......Page 730
Drop Thresholds......Page 731
Trust Boundries......Page 732
Supervisor and Switching Engine......Page 734
Policy Feature Card......Page 737
Ethernet Interfaces......Page 738
QoS Flow on the Catalyst 6500......Page 742
Ingress Queue Scheduling......Page 743
Layer 2 Switching Engine QoS Frame Flow......Page 745
Egress Queue Scheduling......Page 746
Catalyst 6500 QoS Summary......Page 749
Cisco Catalyst 4500/4000 QoS Features......Page 753
Supervisor Engine I and II......Page 754
Supervisor Engine III and IV......Page 755
Cisco Catalyst 3550 QoS Features......Page 757
Cisco Catalyst 3524 QoS Features......Page 758
QoS Configurations on Catalyst Switches......Page 759
Configuration of a Catalyst Switch Using Catalyst OS......Page 760
Configuring QoS for the Catalyst OS Switch......Page 761
CoS-to-Egress Queue Mapping for the Catalyst OS Switch......Page 762
Layer-2-to-Layer 3 Mapping......Page 763
Configuring Trust Boundaries for a Catalyst OS Switch......Page 764
Configuring Untagged Frames for the Catalyst OS Switch......Page 765
Configuring QoS Access Lists in the Catalyst OS Switch......Page 766
Connecting a Catalyst OS Switch to WAN Segments......Page 767
Displaying QoS Settings for the Catalyst OS Switch......Page 768
Configuration of a Catalyst Switch Using IOS......Page 772
Enabling QoS for the Catalyst IOS Switch......Page 773
CoS-to-Egress Queue Mapping for the Catalyst IOS Switch......Page 774
Layer 2-to-Layer 3 Mapping......Page 775
Configuring Trust Boundaries for a Catalyst IOS Switch......Page 776
Configuring QoS Access Lists in the Catalyst IOS Switch......Page 777
Displaying QoS Settings for the Catalyst IOS Switch......Page 779
Foundation Summary......Page 783
Catalyst 6500 Series of Switches......Page 796
Catalyst 3550/3524 Series of Switches......Page 797
Appendix B......Page 0
QoS: Tuning Bandwidth, Delay, Jitter, and Loss......Page 799
Traffic Characteristics of Voice, Video, and Data......Page 800
QoS Tools......Page 806
Differentiated Services......Page 807
Integrated Services......Page 808
Classification and Marking Concepts......Page 813
CAR, PBR, and CB Marking......Page 814
Queuing Concepts......Page 820
CBWFQ and LLQ......Page 821
Comparing Queuing Options......Page 822
Conceptual Questions......Page 823
Priority Queuing and Custom Queuing......Page 824
WFQ......Page 825
CBWFQ, LLQ, IP RTP Priority......Page 826
Comparing Queuing Tool Options......Page 828
Shaping and Policing Concepts......Page 830
Shaping with FRTS, GTS, DTS, and CB Shaping......Page 831
Shaping and Policing Concepts......Page 832
Traffic Shaping......Page 834
Traffic-Policing Tools......Page 836
WRED......Page 837
FRED......Page 838
Congestion-Avoidance Concepts and Random Early Detection (RED)......Page 839
Weighted RED (WRED)......Page 840
Flow-Based WRED (FRED)......Page 842
Compression......Page 843
Link Fragmentation and Interleave......Page 844
Compression Tools......Page 845
LFI Tools......Page 847
Call Admission Control Concepts......Page 851
Local-Based CAC......Page 852
Measurement-Based CAC......Page 853
Resources-Based CAC......Page 854
QoS Design......Page 855
QoS Management......Page 856
QoS Design......Page 858
LAN QoS Concepts......Page 861
Catalyst 6500 Series of Switches......Page 862
Catalyst 4500/4000 Series of Switches......Page 863
Catalyst 3550/3524 Series of Switches......Page 864
Foundation Topics......Page 868
QPPB Route Marking: Step 1......Page 873
QPPB Per-Packet Marking: Step 2......Page 874
QPPB Sample Configuration......Page 876
QPPB: The Hidden Details......Page 878
QPPB Summary......Page 880
Flow-Based dWFQ......Page 898
ToS-Based dWFQ......Page 901
Distributed QoS Group–Based WFQ......Page 904
Summary: dWFQ Options......Page 906
MDRR Configuration......Page 911
