End-to-End Qos Network Design : Quality of Service in LANs, WANs, and VPNs

by Szigeti, Tim; Hattingh, Christina

• ISBN13: 9781587051760
• ISBN10: 1587051761
• Edition: 1st
• Format: Hardcover
• Copyright: 2004-11-09
• Publisher: Cisco Press

Summary

Quality of Service (QoS) has already proven itself as the enabling technology for the convergence of voice, video, and data networks. As business needs evolve, so do the demands for QoS. The need to protect critical applications via QoS mechanisms in business networks has escalated over the past few years, primarily due to the increased frequency and sophistication of denial-of-service (DoS) and worm attacks.

Author Biography

Tim Szigeti, CCIE No. 9794, is part of the Technology Solutions Engineering team within the Cisco Central Technical Marketing organization, where he helps define and drive strategic QoS solutions across Cisco technology groups while working with many Fortune 500 companies (both enterprise and service providers) providing QoS design expertise.

Christina Hattingh is a member of the technical staff in the Multiservice Customer Edge Business Unit of Cisco Systems. In this role, she trains Cisco sales staff and advises customers on voice network deployment and design.

Table of Contents

Introduction	xxii
Part I Introduction to QoS	3	(64)
Introduction to QoS	5	(28)
A Brief Historical Perspective	5	(2)
QoS Evolution	7	(2)
User Network Expectations	9	(1)
End User	9	(1)
Information Technologies Management	9	(1)
Understanding QoS	10	(4)
End-to-End QoS	10	(1)
All Packets Are (Not) Equal	11	(1)
The Challenges of Converged Networks	12	(2)
QoS Models	14	(3)
IntServ Overview	15	(1)
DiffServ Overview	16	(1)
Introduction to the QoS Toolset	17	(2)
Simplifying QoS	19	(7)
Modular QoS Command-Line Interface	19	(1)
QoS Baseline	20	(1)
Default Behavior	21	(3)
Cross-Platform Feature Consistency	24	(1)
Automatic QoS	24	(2)
If I Have AutoQoS, Why Should I Be Reading This Book?	26	(3)
The Continuing Evolution of QoS	29	(1)
Summary	29	(1)
Further Reading	30	(3)
General	30	(1)
IntServ	30	(1)
DiffServ	31	(1)
AutoQoS	31	(2)
QoS Design Overview	33	(34)
QoS Requirements of VoIP	33	(6)
Voice (Bearer Traffic)	33	(5)
Call-Signaling Traffic	38	(1)
QoS Requirements of Video	39	(3)
Interactive-Video	39	(2)
Streaming-Video	41	(1)
QoS Requirements of Data	42	(6)
Best-Effort Data	44	(1)
Bulk Data	44	(1)
Transactional Data/Interactive Data	45	(1)
Locally Defined Mission-Critical Data	45	(2)
DLSw+ Considerations	47	(1)
QoS Requirements of the Control Plane	48	(1)
IP Routing	48	(1)
Network-Management	49	(1)
Scavenger Class	49	(1)
DoS and Worm Mitigation Strategy Through Scavenger Class QoS	50	(4)
Principles of QoS Design	54	(9)
General QoS Design Principles	55	(2)
Classification and Marking Principles	57	(1)
Policing and Markdown Principles	57	(1)
Queuing and Dropping Principles	58	(3)
DoS and Worm Mitigation Principles	61	(1)
Deployment Principles	62	(1)
Summary	63	(1)
Further Reading	64	(3)
Part II QoS Toolset	67	(220)
Classification and Marking Tools	69	(34)
Classification Tools	70	(7)
Modular QoS Command-Line Interface Class Maps	71	(2)
Network-Based Application Recognition	73	(4)
Marking Tools	77	(21)
Class-Based Marking	78	(1)
Class-Based Policing	78	(1)
Committed Access Rate	79	(1)
Policy-Based Routing	79	(1)
Voice Gateway Packet Marking	79	(2)
Layer 2 Marking Fields	81	(5)
Layer 3 Marking Fields	86	(4)
Translating Layer 2 and Layer 3 Packet Markings	90	(8)
Summary	98	(1)
Further Reading	99	(4)
General	99	(1)
DiffServ	99	(1)
L2 Protocol Tunneling	100	(1)
VPN	100	(1)
NBAR	100	(1)
MPLS	100	(1)
IP--ATM/Frame Relay Bundles	101	(1)
Level 2 to Level 3 Packet-Marking Translation	101	(2)
Policing and Shaping Tools	103	(30)
Token Bucket Algorithms	105	(2)
Policers	107	(11)
Policers as Markers	107	(1)
Committed Access Rate	107	(2)
Class-Based Policing	109	(9)
Shapers	118	(10)
Shaping Algorithms	120	(1)
Shaping on ATM and Frame Relay Networks	121	(5)
Generic Traffic Shaping	126	(1)
Class-Based Shaping	126	(2)
Further Reading	128	(5)
DiffServ Policing Standards	128	(1)
Policing	129	(1)
ATM PVC Traffic Parameters	129	(1)
Frame Relay Traffic Shaping	129	(1)
Traffic Shaping	130	(3)
Congestion-Management Tools	133	(26)
Understanding Scheduling and Queuing	134	(2)
Legacy Layer 3 Queuing Mechanisms	136	(3)
Priority Queuing	137	(1)
Custom Queuing	137	(1)
Weighted Fair Queuing	137	(2)
IP RTP Priority Queuing	139	(1)
Currently Recommended Layer 3 Queuing Mechanisms	139	(11)
Class-Based Weighted Fair Queuing	139	(1)
Low-Latency Queuing	140	(10)
Layer 2 Queuing Tools	150	(2)
Frame Relay Dual-FIFO	150	(1)
PVC Interface Priority Queuing	150	(2)
Tx-ring	152	(1)
PAK_priority	153	(1)
Summary	154	(1)
Further Reading	154	(5)
Layer 3 Queuing	154	(1)
Layer 2 Queuing	155	(1)
Tx-ring	156	(1)
PAK_priority	156	(3)
Congestion-Avoidance Tools	159	(10)
Random Early Detection	160	(1)
Weighted Random Early Detection	161	(1)
DSCP-Based Weighted Random Early Detection	162	(1)
Explicit Congestion Notification	163	(3)
Summary	166	(1)
Further Reading	166	(3)
DiffServ Standards Relating to WRED	166	(1)
Cisco IOS WRED Documentation	166	(3)
Link-Specific Tools	169	(26)
Header-Compression Techniques	170	(11)
Related Standards	171	(1)
TCP Header Compression	171	(1)
RTP Header Compression	171	(2)
Compression Formats	173	(1)
Layer 2 Encapsulation Protocol Support	174	(3)
Summary of cRTP Formats and Protocol Encapsulations	177	(1)
Class-Based Header Compression	178	(2)
Advanced Topics on cRTP	180	(1)
Link Fragmentation and Interleaving	181	(9)
Fragment Sizes	183	(1)
Multilink PPP LFI	183	(2)
Frame-Relay Fragmentation	185	(3)
LFI for Frame Relay/ATM Service Interworking	188	(2)
IPSec Prefragmentation	190	(1)
Summary	190	(1)
Further Reading	191	(4)
General	191	(1)
IETF Standards	191	(1)
Frame Relay Forum Standards	191	(1)
Header Compression	192	(1)
Link Fragmentation and Interleaving	192	(3)
Bandwidth Reservation	195	(10)
RSVP Overview	196	(3)
RSVP Service Types	197	(1)
Admission Control	197	(1)
RSVP and LLQ	198	(1)
MPLS Traffic Engineering	199	(1)
Scalability	200	(1)
RSVP-DiffServ Integration	200	(1)
Endpoints and Proxies	201	(1)
Summary	201	(1)
Further Reading	201	(4)
Standards	201	(1)
Cisco IOS Documentation	202	(3)
Call Admission Control (CAC)	205	(18)
CAC Overview	205	(1)
CAC Defined	206	(1)
CAC Tool Categories	207	(2)
Local CAC Tools	208	(1)
Measurement-Based CAC Tools	208	(1)
Resource-Based CAC Tools	208	(1)
CallManager Locations CAC	209	(2)
Gatekeeper CAC	211	(1)
RSVP	212	(6)
Example of VoIP CAC Through RSVP	215	(3)
Summary	218	(1)
Further Reading	218	(5)
General	218	(1)
Cisco IOS Documentation	218	(5)
Catalyst QoS Tools	223	(46)
Generic Catalyst QoS Models	224	(7)
Classification, Marking, and Mapping	224	(3)
Policing and Markdown	227	(1)
Queuing and Dropping	228	(3)
Catalyst 2950	231	(4)
Catalyst 2950 Classification, Marking, and Mapping	232	(2)
Catalyst 2950 Policing and Markdown	234	(1)
Catalyst 2950 Queuing	235	(1)
Catalyst 3550	235	(7)
Catalyst 3550 Classification, Marking, and Mapping	237	(1)
Catalyst 3550 Policing and Markdown	238	(2)
Catalyst 3550 Queuing and Dropping	240	(2)
Catalyst 2970, 3650, and 3750	242	(5)
Catalyst 2970/3560/3750 Classification, Marking, and Mapping	243	(1)
Catalyst 2970/3560/3750 Policing and Markdown	244	(1)
Catalyst 2970/3560/3750 Queuing and Dropping	244	(3)
Catalyst 4500	247	(5)
Catalyst 4500 Classification, Marking, and Mapping	248	(1)
Catalyst 4500 Policing and Markdown	249	(1)
Catalyst 4500 Queuing and Dropping	250	(2)
Catalyst 6500	252	(11)
Catalyst 6500 Classification, Marking, and Mapping	254	(3)
Catalyst 6500 Policing and Markdown	257	(2)
Catalyst 6500 Queuing and Dropping	259	(4)
Summary	263	(3)
Further Reading	266	(3)
WLAN QoS Tools	269	(18)
QoS for Wireless LANs Versus QoS on Wired LANs	270	(1)
Upstream Versus Downstream QoS	271	(1)
IEEE 802.11 DCF	272	(3)
Interframe Spaces	272	(1)
Random Backoffs/Contention Windows	273	(2)
IEEE 802.11e EDCF	275	(4)
QoS Basic Service Set Information Element	278	(1)
IEEE 802.1D Classes of Service	279	(1)
QoS Operation on Cisco APs	280	(1)
Configuring QoS on Cisco APs	281	(3)
Summary	284	(1)
Further Reading	285	(2)
Part III LAN QoS Design	287	(158)
Campus QoS Design	289	(156)
DoS/Worm-Mitigation Strategies	292	(3)
Scavenger-Class QoS Operation	294	(1)
Call-Signaling TCP/UDP Ports in Use	295	(7)
Access-Edge Trust Models	302	(12)
Trusted Endpoint Models	302	(2)
Untrusted Endpoint Models	304	(3)
Conditionally Trusted Endpoint(s) Models	307	(7)
Catalyst 2950 QoS Considerations and Design	314	(11)
Catalyst 2950: Trusted Endpoint Model	314	(1)
Catalyst 2950: Untrusted PC with SoftPhone Model	315	(1)
Catalyst 2950: Untrusted Server Model	315	(4)
Catalyst 2950: Conditionally Trusted IP Phone + PC: Basic Model	319	(3)
Catalyst 2950: Conditionally Trusted IP Phone + PC: Advanced Model	322	(1)
Catalyst 2950: Queuing	322	(3)
Catalyst 3550 QoS Considerations and Design	325	(17)
Catalyst 3550: Trusted Endpoint Model	327	(1)
Catalyst 3550: Untrusted PC with SoftPhone Model	327	(3)
Catalyst 3550: Untrusted Server Model	330	(1)
Catalyst 3550: Conditionally Trusted IP Phone + PC: Basic Model	331	(2)
Catalyst 3550: Conditionally Trusted IP Phone + PC: Advanced Model	333	(3)
Catalyst 3550: Queuing and Dropping	336	(6)
Catalyst 2970/3560/3750 QoS Considerations and Design	342	(15)
Catalyst 2970/3560/3750: Trusted Endpoint Model	343	(1)
Catalyst 2970/3560/3750: Untrusted PC with SoftPhone Model	344	(1)
Catalyst 2970/3560/3750: Untrusted Server Model	345	(1)
Catalyst 2970/3560/3750: Conditionally Trusted IP Phone + PC: Basic Model	346	(2)
Catalyst 2970/3560/3750: Conditionally Trusted IP Phone + PC: Advanced Model	348	(3)
Catalyst 2970/3560/3750: Queuing and Dropping	351	(6)
Catalyst 4500-SupII+/III/IV/V QoS Considerations and Design	357	(15)
Catalyst 4500: Trusted Endpoint Model	359	(1)
Catalyst 4500: Untrusted PC with SoftPhone Model	359	(1)
Catalyst 4500: Untrusted Server Model	360	(2)
Catalyst 4500: Conditionally Trusted IP Phone + PC: Basic Model	362	(2)
Catalyst 4500: Conditionally Trusted IP Phone + PC: Advanced Model	364	(2)
Catalyst 4500: Queuing	366	(6)
Catalyst 6500 QoS Considerations and Design	372	(48)
Catalyst 6500: CatOS Defaults and Recommendations	375	(1)
Catalyst 6500: Trusted Endpoint Model	375	(3)
Catalyst 6500: Untrusted PC with SoftPhone Model	378	(5)
Catalyst 6500: Untrusted Server Model	383	(3)
Catalyst 6500: Conditionally Trusted IP Phone + PC: Basic Model	386	(1)
Catalyst 6500: Conditionally Trusted IP Phone + PC: Advanced Model	387	(4)
Catalyst 6500: Queuing and Dropping	391	(28)
Catalyst 6500: PFC3 Distribution-Layer (Cisco IOS) Per-User Microflow Policing	419	(1)
WAN Aggregator/Branch Router Handoff Considerations	420	(2)
Case Study: Campus QoS Design	422	(18)
Summary	440	(1)
Further Reading	441	(4)
Part IV WAN QoS Design	445	(100)
WAN Aggregator QoS Design	447	(66)
Where Is QoS Needed over the WAN?	447	(1)
WAN Edge QoS Design Considerations	448	(5)
Software QoS	448	(1)
Bandwidth Provisioning for Best-Effort Traffic	449	(1)
Bandwidth Provisioning for Real-Time Traffic	449	(1)
Serialization	450	(1)
IP RTP Header Compression	451	(1)
Tx-ring Tuning	451	(1)
PAK_priority	452	(1)
Link Speeds	452	(1)
Distributed Platform QoS and Consistent QoS Behavior	453	(1)
WAN Edge Classification and Provisioning Models	453	(14)
Slow/Medium Link-Speed QoS Class Models	454	(5)
High Link Speed QoS Class Models	459	(8)
WAN Edge Link-Specific QoS Design	467	(38)
Leased Lines	467	(11)
Frame Relay	478	(10)
ATM	488	(9)
ATM-to-Frame Relay Service Interworking	497	(4)
ISDN	501	(4)
Case Study: WAN Aggregation Router QoS Design	505	(2)
Summary	507	(1)
Further Reading	508	(5)
Branch Router QoS Design	513	(32)
Branch WAN Edge QoS Design	514	(3)
Unidirectional Applications	514	(3)
Branch Router LAN Edge QoS Design	517	(18)
DSCP-to-CoS Remapping	518	(1)
Branch-to-Campus Classification and Marking	519	(7)
NBAR Known-Worm Classification and Policing	526	(9)
Case Study: Branch Router QoS Design	535	(6)
Summary	541	(1)
Further Reading	541	(4)
Part V VPN QoS Design	545	(156)
MPLS VPN QoS Design	547	(88)
Where Is QoS Needed over an MPLS VPN?	548	(2)
Customer Edge QoS Design Considerations	550	(13)
Layer 2 Access (Link-Specific) QoS Design	550	(1)
Service-Provider Service-Level Agreements	551	(1)
Enterprise-to-Service Provider Mapping Models	552	(11)
Provider-Edge QoS Considerations	563	(19)
Service Provider-to-Enterprise Models	563	(3)
MPLS DiffServ Tunneling Modes	566	(16)
Core QoS Considerations	582	(34)
Aggregate Bandwidth Overprovisioning	583	(1)
DiffServ in the Backbone	583	(4)
MPLS Traffic Engineering	587	(29)
Case Study: MPLS VPN QoS Design (CE/PE/P Routers)	616	(16)
Summary	632	(1)
Further Reading	632	(3)
IPSec VPN QoS Design	635	(66)
Site-to-Site V3PN QoS Considerations	637	(21)
IPSec VPN Modes of Operation	637	(3)
Packet Overhead Increases	640	(3)
cRTP and IPSec Incompatibility	643	(1)
Prefragmentation	644	(1)
Bandwidth Provisioning	645	(1)
Logical Topologies	646	(1)
Delay Budget Increases	647	(1)
ToS Byte Preservation	648	(1)
QoS Pre-Classify	649	(2)
Pre-Encryption Queuing	651	(3)
Anti-Replay Implications	654	(3)
Control Plane Provisioning	657	(1)
Site-to-Site V3PN QoS Designs	658	(7)
Headend VPN Edge QoS Options for Site-to-Site V3PNs	665	(1)
Teleworker V3PN QoS Considerations	666	(16)
Teleworker Deployment Models	667	(4)
Broadband-Access Technologies	671	(3)
Bandwidth Provisioning	674	(3)
Asymmetric Links and Unidirectional QoS	677	(1)
Broadband Serialization Mitigation Through TCP Maximum Segment Size Tuning	678	(1)
Split Tunneling	679	(3)
Teleworker V3PN QoS Designs	682	(4)
Case Study: IPSec VPN QoS Design	686	(10)
Summary	696	(1)
Further Reading	697	(4)
Appendix QoS ``At-A-Glance'' Summaries	701	(12)
Index	713