Preface xvii PART I PRELIMINARIES 1 Introduction to VoIP Networks 3 1.1 Public Switched Telephone Network (PSTN) 3 1.2 Fundamentals of Internet technology 7 1.3 Performance issues in the Internet 11 1.4 Quality of Service (QoS) guarantees 12 1.5 Summary 15 2 Basics of VoIP 17 2.1 Packetization of voice 17 2.2 Networking technology 18 2.

3 Architecture overview 18 2.4 Process of making a VoIP call 22 2.5 Deployment issues 23 2.6 VoIP applications and services 26 2.7 Summary 27 3 VoIP Codecs 29 3.1 Codec design overview 29 3.2 Speech coding techniques 31 3.3 Narrowband codecs 34 3.

4 Wideband and multirate codecs 36 3.5 VoIP softwares 37 3.6 Summary 38 4 Performance of Voice Codecs 41 4.1 Factors affecting VoIP quality 41 4.2 Voice quality assessment 43 4.3 Subjective measures and MOS score 44 4.4 Conversational opinion score 45 4.5 E-Model 46 4.

6 Sensitivity to loss 48 4.7 Perceptual Evaluation of Speech Quality (PESQ) 50 4.8 Tools for lab testbed setup 53 4.9 Voice input/output tools 55 4.10 Summary 57 5 VoIP Protocols 59 5.1 Introduction 59 5.2 Signaling protocols 61 5.3 Media transport protocols 70 5.

4 Summary 71 PART II VOIP IN OVERLAY NETWORKS 6 Overlay Networks 75 6.1 Internet communication overview 75 6.2 Limitations of the Internet 77 6.3 Overlay networks 78 6.4 Applications of overlay networks 82 6.5 Summary 86 7 P2P Technology 87 7.1 P2P communication overview 87 7.2 Classification of P2P networks 89 7.

3 Unstructured overlays 90 7.4 Structured overlays - Distributed Hash Tables (DHTs) 92 7.5 Types of DHT 96 7.6 Semi-structured overlays 100 7.7 Keyword search using DHT 101 7.8 Summary 102 8 VoIP over Infrastructure Overlays 103 8.1 Introduction 104 8.2 VoIP over overlay - generic architecture 104 8.

3 Methods to enhance VoIP quality 105 8.4 Estimating network quality 110 8.5 Route computation 114 8.6 Perceived enhancement of VoIP quality 115 8.7 Summary 116 9 VoIP over P2P 119 9.1 VoIP over P2P overlay - generic architecture 119 9.2 VoIP issues in P2P overlay 120 9.3 Case study: Skype 122 9.

4 Standardization 130 9.5 Summary 130 PART III VOIP IN WIRELESS NETWORKS 10 IEEE 802.11 Wireless Networks 135 10.1 Network architecture overview 135 10.2 Network access management 137 10.3 Basic medium access protocol 139 10.4 Physical layer 142 10.5 Network resource management 144 10.

6 IEEE 802.11 standardization overview 147 10.7 Summary 148 11 Voice over IEEE 802.11 Wireless Networks 149 11.1 VoIP overWLAN performance problems 149 11.2 VoIP capacity 151 11.3 VoIP packet prioritization 155 11.4 Handoff performance 157 11.

5 Reliable delivery 160 11.6 Client power management 161 11.7 Issues in mesh networks 161 11.8 Summary 163 12 IEEE 802.16 WiMAX 165 12.1 WiMAX overview 165 12.2 IEEE 802.11 MAC protocol architecture 166 12.

3 MAC layer framing 168 12.4 Physical layer 170 12.5 Radio resource management 174 12.6 Competing technologies 175 12.7 Summary 176 13 Voice over WiMAX 177 13.1 Introduction 177 13.2 VoIP service delivery overWiMAX network 178 13.3 QoS architecture 179 13.

4 Call admission control 181 13.5 Uplink QoS control 181 13.6 Enhanced QoS control for VoIP 182 13.7 MAC enhancement strategies 185 13.8 Comparison with competing technologies 187 13.9 Summary 187 PART IV VOIP IN ENTERPRISE NETWORKS 14 Private Branch Exchange (PBX) 191 14.1 Private Branch Exchange (PBX) 191 14.2 Case study: Asterisk open-source IP-PBX 195 14.

3 Summary 206 15 Network Address Translation (NAT) and Firewall 207 15.1 Introduction 208 15.2 NAT fundamentals 208 15.3 Applications of NAT 210 15.4 Types of NAT 212 15.5 Firewall 214 15.6 NAT traversal solutions 214 15.7 NAT traversal in H.

323 219 15.8 Summary 220 PART V VOIP SERVICE DEPLOYMENT 16 Supporting Services and Applications 223 16.1 Domain Name System (DNS) 223 16.2 ENUM 225 16.3 Network monitoring 225 16.4 Direct Inward Dialing (DID) 226 16.5 Emergency calling (911) 226 16.6 Fax 227 16.

7 Summary 228 17 Security and Privacy 231 17.1 Security and privacy issues 232 17.2 Generic issues 232 17.3 VoIP-related issues 234 17.4 Solutions 236 17.5 Recommendations 239 17.6 Summary 240 18 IP Multimedia Subsystem (IMS) 241 18.1 Introduction 241 18.

2 Architecture design goals 242 18.3 IMS advantages 243 18.4 IMS architecture organization 244 18.5 Network Attachment SubSystem (NASS) 246 18.6 Resource Admission Control Subsystem (RACS) 247 18.7 IMS core subsystem 247 18.8 IMS QoS management 249 18.9 QoS provisioning approach 249 18.

10 Summary 251 Index 253.