VPN applications guide Book

	Networking Council Foreword	xiii
	Acknowledgments	xiv
	Preface	xv
Chapter 1	Introduction and Overview	1
	A Brief History of Public Communication Networks	1
	Why Enterprises Build Private Networks	4
	One Size Does Not Fit All	4
	Cutting Costs	4
	Controlling Communication	5
	Achieving Connectivity	5
	What Makes a Private Network Virtual?	6
	Private Line-Based Networks	6
	Circuit-Switched VPNs	8
	Connection-Oriented VPNs	9
	Connectionless VPNs	12
	Basic Economics of VPNs	14
	Business Drivers and Environment	15
	Government Regulation and Deregulation	15
	Government-Funded Innovation	17
	Managing the Bottom Line	18
	Innovation as a Necessity for Survival	18
	Addressing Global Needs	19
	Need to Protect Sensitive Information	20
	Quality of Service, Capacity, and Service-Level Agreements	20
	Technology Trends and Enablers	21
	Wavelengths and Optical Switching	22
	Overcoming the Limitations of Moore's Law	22
	Access--The Perennial Bottleneck	23
	Integrating Voice and Data Services	24
	Traffic Management, Queue Scheduling, and Congestion Control	25
	A Cornucopia of Internet Protocols	26
Chapter 2	Private Network Technologies	27
	Private Transmission Media	27
	Digital Private Lines	27
	Digital Subscriber Lines and Cable Modems	36
	Satellite and Wireless Media	38
	Private Voice Networks	38
	Private Branch Exchanges (PBXes)	38
	Cost Savings of Private Voice Networks	39
	Additional Benefits and Offsetting Expenses	42
	Integrated Services Digital Network (ISDN)	43
	Private Data Networks	44
	Mainframe Computers and Early Data Networks	44
	Advent of PCs and Local Area Networks	47
	Multiprotocol Data Networking	50
Chapter 3	Circuit-Switched VPNs	53
	Business Drivers	54
	Impact of Deregulation and Competition	54
	Unforeseen Expenses of a Private Network	55
	Need for Ubiquitous Access	55
	Increasing Need for Data Communication	56
	Heightened Security and Productivity Needs	56
	Technology Trends and Enablers	56
	Computerized Telephone Switches	57
	High-Performance Transaction Processing	57
	High-Performance Data Communication	58
	Implementations and Protocols	58
	Common Channel Signaling	58
	Call Processing and Intelligence	61
	Intelligent Network Architectures	63
	Voice over Data and Intelligent Networking	67
	Circuit-Switched VPN Applications	69
	On-Net and Off-Net Access Methods	69
	Private Numbering Plans	71
	Originating and Terminating Call Screening	73
	Authorization and Accounting Codes	75
	Overflow and Internetwork Routing	76
	Feature Interaction	78
Chapter 4	Early Connection-Oriented Data VPNs--X.25 and Frame Relay	79
	Business Drivers and Requirements	80
	Inflexibility and Cost of Private Lines	80
	Bursty Traffic of Interactive Data Applications	80
	Emergence of Data Applications	81
	Declining Cost of Computing and Memory	82
	Technology Trends and Enablers	82
	Impact of Transmission Media on Performance	82
	Continuing Improvements in Packet Switching	86
	Layered Data Communications Protocols	86
	Implementation and Protocol Specifics	88
	Connection-Oriented Packet Switching	88
	X.25 Packet Switching	90
	X.25 Closed User Groups (CUGs)	92
	Frame Relaying	93
	Early Traffic Management Capabilities	95
	Principal Applications	101
	Private Line Network Replacement	101
	Cost-Effective Hierarchical Networks	102
	Supporting Private Multiprotocol Networks	103
	Integrating Voice and Data with Frame Relay	105
Chapter 5	Modern Connection-Oriented VPNs--ATM, MPLS, and RSVP	107
	Business Drivers and Requirements	107
	Guaranteed Capacity and Quality	108
	The Need for Speed	109
	Continual Cost Reduction	110
	Technology Trends and Enablers	110
	Making Switching Hardware Run Fast	110
	QoS and Traffic Management	111
	Packetization for Voice, Video, and Circuit Data	116
	Implementation and Protocol Specifics	116
	Connection-Oriented Protocol Relationships	116
	The ATM Cell	119
	ATM Adaptation Layers (AALs)	120
	ATM QoS andService Categories	123
	MultiProtocol Label Switching (MPLS)	126
	Integrated Services and the Resource reSerVation Protocol (RSVP)	127
	Switched and Permanent Virtual Connections--SVCs and PVCs	128
	Admission Control and Statistical Multiplexing	131
	QoS-Aware, Capacity-Constrained Routing	133
	Principal Applications	134
	Integrating Voice, Data, and Video	134
	Hierarchical Connection-Oriented VPNs	135
	Interworking between RSVP and ATM	136
Chapter 6	The Internet Protocol Suite	139
	Business Drivers and Requirements	139
	Killer Applications: Email and the Web	140
	The Value of Ubiquity	141
	Changing Business Paradigms	141
	Technology Trends and Enablers	142
	IP over Anything	142
	Scalability of Connectionless Routing	144
	High-Performance Routers	146
	Implementation and Protocol Specifics	146
	The TCP/IP Protocol Suite	147
	Building Blocks of TCP/IP Networks	148
	IP Packet Format and Address Usage	152
	IP Routing: The Connectionless Cornerstone	156
	Policy-Based Routing--The Border Gateway Protocol (BGP)	158
	Connectionless UDP Support for Voice, Video, and Network Management	166
	Connection-Oriented TCP Support for Email, the Web, and File Transfer	167
	User-Friendly Names Instead of Numbers--Domain Name Service (DNS)	172
	Principal Applications	174
	The Global Internet	174
	Electronic Mail, Commerce, and Library	175
	Shared Infrastructure for Internet-Based VPNs	177
Chapter 7	Building Blocks for IP-Based VPNs--Security, Quality, and Access	179
	Business Drivers and Requirements	179
	Privacy Problems in the Public Internet	180
	Need for Quality to the End User	181
	Technology Trends and Enablers	182
	Emergence of the Science of Crytography	182
	The Scalable Evolution of QoS	184
	Security--Keeping Important Information Private	184
	Cryptographic Systems	185
	Symmetric Secret-Key Cryptosystems	186
	Asymmetric Public-Key Crytosystems	189
	Hashing, Digital Signatures, and Message Authentication Codes	194
	Key Management Systems	195
	QoS in a Connectionless Network	199
	Differentiated Services (diffserv)	199
	Real-Time Transport Protocol (RTP)	201
	Access Tools and Techniques	204
	Packet Filters and Firewalls	204
	Handling Private Addresses--Network Address Translation	206
Chapter 8	Dial-In Access and Multiprotocol Tunneling VPNs	209
	Business Drivers and Requirements	209
	Empowering the Mobile Workforce	210
	Leveraging Economics of the Shared Internet	210
	Technology Trends and Enablers	211
	Increasing Use of the Internet Protocol	211
	Positively Authenticating a User's Identity	212
	Extending the Secured LAN via Tunneling	212
	Implementation and Protocol Specifics	213
	Generic Secure Dial-In Access Architecture	213
	Point-to-Point Protocol (PPP)	214
	Authentication Protocols--PAP and CHAP	215
	Extensible Authentication Protocol (EAP)	217
	Access Control Protocols--TACACS and RADIUS	219
	Tunneling Protocol Standards	220
	Point-to-Point Tunneling Protocol (PPTP)	221
	Layer 2 Tunneling Protocol (L2TP)	224
	Principal Applications	226
	Dial-In Terminal Servers versus Secured Internet Access	226
	Connection-Oriented versus IP-Based VPNs	230
Chapter 9	IP Security-Enabled and Routing-Controlled VPNs	235
	Business Drivers and Requirements	235
	Competition among Security Vendors	235
	Outsourced and Service Provider VPNs	236
	Technology Trends and Enablers	236
	Security Standards and Public Key Infrastructure	237
	The Good and Bad Things about Standards	237
	Implementation and Protocol Specifics	238
	IP Security Protocol Suite (IPsec)	238
	BGP Extensions in Support of VPNs	251
	BGP-Controlled MPLS VPN	253
	Principal Applications	260
	Secured VPN Access and the Public Internet	261
	Typical IP VPN Deployment Scenarios	262
Chapter 10	The Future of VPNs	265
	Planning and Implementing a VPN	265
	Collecting Requirements and Establishing Goals	266
	Analyzing Alternatives and Decision Making	268
	Migrating and Operating the New Network	269
	Learn from What Others Have Done	270
	Technology, Protocol, and Standards Directions and Trends	272
	Will One Size Ever Fit All?	272
	Riding the Wave of Internet Growth	273
	The Inevitable Delivery of QoS over the Internet	276
	Expansion of Applications and Services	278
	VPNs in the Twenty-First Century	279
	Lessons of the Marketplace	280
	Sustaining and Disruptive Technologies	281
	Changing Role of the Enterprise in Society	283
	Glossary	285
	References	307
	Index	321