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Translates technical jargon into practical business communications solutions This book takes readers from traditional voice, fax, video, and data services delivered via separate platforms to a single, unified platform delivering all of these services seamlessly via the Internet. With its clear, jargon-free explanations, the author enables all readers to better understand and assess the growing number of voice over Internet protocol (VoIP) and unified communications (UC) products and services that are available for businesses. VoIP and Unified Communications is based on the author's careful…mehr
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Translates technical jargon into practical business communications solutions
This book takes readers from traditional voice, fax, video, and data services delivered via separate platforms to a single, unified platform delivering all of these services seamlessly via the Internet. With its clear, jargon-free explanations, the author enables all readers to better understand and assess the growing number of voice over Internet protocol (VoIP) and unified communications (UC) products and services that are available for businesses.
VoIP and Unified Communications is based on the author's careful review and synthesis of more than 7,000 pages of published standards as well as a broad range of datasheets, websites, white papers, and webinars. It begins with an introduction to IP technology and then covers such topics as:
Packet transmission and switching
VoIP signaling and call processing
How VoIP and UC are defining the future
Interconnections with global services
Network management for VoIP and UC
This book features a complete chapter dedicated to cost analyses and payback calculations, enabling readers to accurately determine the short- and long-term financial impact of migrating to various VoIP and UC products and services. There's also a chapter detailing major IP systems hardware and software. Throughout the book, diagrams illustrate how various VoIP and UC components and systems work. In addition, the author highlights potential problems and threats to UC services, steering readers away from common pitfalls.
Concise and to the point, this text enables readers--from novices to experienced engineers and technical managers--to understand how VoIP and UC really work so that everyone can confidently deal with network engineers, data center gurus, and top management.
This book takes readers from traditional voice, fax, video, and data services delivered via separate platforms to a single, unified platform delivering all of these services seamlessly via the Internet. With its clear, jargon-free explanations, the author enables all readers to better understand and assess the growing number of voice over Internet protocol (VoIP) and unified communications (UC) products and services that are available for businesses.
VoIP and Unified Communications is based on the author's careful review and synthesis of more than 7,000 pages of published standards as well as a broad range of datasheets, websites, white papers, and webinars. It begins with an introduction to IP technology and then covers such topics as:
Packet transmission and switching
VoIP signaling and call processing
How VoIP and UC are defining the future
Interconnections with global services
Network management for VoIP and UC
This book features a complete chapter dedicated to cost analyses and payback calculations, enabling readers to accurately determine the short- and long-term financial impact of migrating to various VoIP and UC products and services. There's also a chapter detailing major IP systems hardware and software. Throughout the book, diagrams illustrate how various VoIP and UC components and systems work. In addition, the author highlights potential problems and threats to UC services, steering readers away from common pitfalls.
Concise and to the point, this text enables readers--from novices to experienced engineers and technical managers--to understand how VoIP and UC really work so that everyone can confidently deal with network engineers, data center gurus, and top management.
Produktdetails
- Produktdetails
- Verlag: Wiley & Sons
- Artikelnr. des Verlages: 1W118019210
- 1. Auflage
- Seitenzahl: 320
- Erscheinungstermin: 20. März 2012
- Englisch
- Abmessung: 234mm x 156mm x 18mm
- Gewicht: 532g
- ISBN-13: 9781118019214
- ISBN-10: 1118019210
- Artikelnr.: 33275135
- Verlag: Wiley & Sons
- Artikelnr. des Verlages: 1W118019210
- 1. Auflage
- Seitenzahl: 320
- Erscheinungstermin: 20. März 2012
- Englisch
- Abmessung: 234mm x 156mm x 18mm
- Gewicht: 532g
- ISBN-13: 9781118019214
- ISBN-10: 1118019210
- Artikelnr.: 33275135
WILLIAM A. FLANAGAN is President and founder of Flanagan Consulting. With three decades of telecommunications experience, Mr. Flanagan is an expert in voice and data technologies, products, markets, and customers. His network designs have solved problems for enterprises, government agencies, and carriers.
Preface xiii Acknowledgments xv 1 IP Technology Disrupts Voice Telephony 1 1.1 Introduction to the Public Switched Telephone Network
1 1.2 The Digital PSTN
2 1.3 The Packet Revolution in Telephony
8 1.3.1 Summary of Packet Switching
9 1.3.2 Link Capacity: TDM versus Packets
11 1.3.3 VoIP and "The Cloud"
13 IN SHORT: Reading Network Drawings
14 2 Traditional Telephones Still Set Expectations 17 2.1 Availability: How the Bell System Ensured Service
18 2.2 Call Completion
19 2.3 Sound Quality: Encoding for Recognizable Voices
20 2.4 Low Latency
23 2.5 Call Setup Delays
24 2.6 Impairments Controlled: Echo, Singing, Distortion, Noise
25 3 From Circuits to Packets 27 3.1 Data and Signaling Preceded Voice
27 3.1.1 X.25 Packet Data Service
27 3.1.2 SS7: PSTN Signaling on Packets
28 3.1.3 ISDN
29 3.2 Putting Voice into Packets
30 3.2.1 Voice Encoding
31 3.2.2 Dicing and Splicing Voice Streams
32 3.2.3 The Latency Budget
33 4 Packet Transmission and Switching 37 4.1 The Physical Layer: Transmission
39 IN SHORT: The Endian Wars
40 4.2 Data Link Protocols
41 4.3 IP, the Network Protocol
43 4.4 Layer 4 Transport Protocols
47 4.4.1 Transmission Control Protocol
47 4.4.2 User Datagram Protocol
50 4.4.3 Stream Control Transmission Protocol
51 4.5 Higher Layer Processes
54 4.5.1 RTP
54 4.5.2 RTCP
57 4.5.3 Multiplexing RTP and RTCP on One UDP Port
58 4.5.4 RTP Mixers and Translators
59 4.5.5 Layered Encoding
60 4.5.6 Profiles for Audio and Video Conferences
60 4.5.7 Security via Encryption
61 IN SHORT: Public Key Infrastructure (PKI)
62 4.6 Saving Bandwidth
64 4.6.1 Voice Compression
64 4.6.2 Header Compression
66 4.6.3 Silence Suppression, VAD
67 4.6.4 Sub-Packet Multiplexing
69 4.6.5 Protocol and Codec Selection
70 4.7 Differences: Circuit versus Packet Switched
71 4.7.1 Power to the Desktop Phone
71 4.7.2 Phone as Computer and Computer as Phone
72 4.7.3 Length of a Phone Line
72 4.7.4 Scaling to Large Size
75 4.7.5 Software Ownership and Licenses
75 5 VoIP Signaling and Call Processing 77 5.1 What Packet Voice and UC Systems Share
78 5.2 Session Initiation Protocol (SIP)
80 5.2.1 SIP Architecture
81 5.2.2 SIP Messages
88 5.2.3 SIP Header Fields and Behaviors
94 5.3 Session Description Protocol
101 IN SHORT: ABNF
104 5.4 Media Gateway Control Protocol
107 5.4.1 MGW Functions
107 5.4.2 MGW Connection Model
110 5.4.3 Megaco Procedures
112 5.4.4 Megaco Details
115 5.4.5 Signaling Conversion
119 5.4.6 Voice Transcoding
119 5.5 H.323
120 5.5.1 H.323 Architecture
121 5.5.2 Gatekeeper
123 5.5.3 Gateway
126 5.5.4 Terminal
126 5.5.5 Multipoint Control Unit
127 5.5.6 Call Procedures
128 5.6 Directory Services
134 5.6.1 Domain Name Service (DNS)
134 5.6.2 ENUM
135 6 VoIP and Unified Communications Define the Future 139 6.1 Voice as Before, with Additions
139 6.2 Legacy Services to Keep and Improve with VoIP
140 6.2.1 Flexible Call Routing and 800 Numbers
141 6.2.2 Call on Hold
141 6.2.3 Call Transfer
142 6.2.4 Call Forwarding
142 6.2.5 Audio Conferencing
142 6.2.6 Video Conferencing
143 6.2.7 Local Number Portability
144 6.2.8 Direct Inward Dialing, Dialed Number Indication
144 6.2.9 Call
Message Waiting
145 6.2.10 Call Recording
146 6.2.11 Emergency Calling (E911)
146 6.2.12 Tracking IP Phone Locations for E911
150 6.3 Facsimile Transmission
153 6.3.1 Facsimile on the PSTN
153 6.3.2 Real-Time Fax over IP: Fax Relay or T.38
155 6.3.3 Store-and-Forward Fax Handling
160 6.3.4 IP Faxing over the PSTN
161 6.4 Phone Features Added with VoIP
UC
162 6.4.1 Presence
163 6.4.2 Forking
163 6.4.3 Voicemail1
4eMail
163 6.4.4 SMS Integration
164 6.4.5 Instant Messaging
165 6.4.6 Webinar Broadcasts
168 6.4.7 Telepresence
168 6.4.8 More UC Features to Consider
168 7 How VoIP and UC Impact the Network 171 7.1 Space, Power, and Cooling
171 7.2 Priority for Voice, Video, Fax Packets
172 7.3 Packets per Second
174 7.4 Bandwidth
174 7.5 Security Issues
175 7.5.1 Eavesdropping and vLAN Hopping
176 7.5.2 Access Controls for Users and Connections
176 7.5.3 Modems
177 7.5.4 DNS Cache Poisoning
177 IN SHORT: Earliest Instance of DNS Cache Poisoning
179 7.5.5 Toll Fraud
179 7.5.6 Pay-per-Call Scams
179 7.5.7 Vishing
180 7.5.8 SIP Scanning
SPIT
180 7.5.9 Opening the Firewall to Incoming Voice
181 7.6 First Migration Steps While Keeping Legacy Equipment
181 7.6.1 Circuit-Switched PBX
182 7.6.2 Digital Phones
182 7.6.3 Analog Phones and FX Service
183 7.6.4 Facsimile Machines
184 7.6.5 Modems
185 8 Interconnections to Global Services 187 8.1 Media Gateways
188 8.2 SIP Trunking
192 8.3 Operating VoIP Across Network Address Translation
196 8.3.1 Failures of SIP, SDP (Signaling)
199 8.3.2 Failures of RTP (Media)
199 8.3.3 Solutions
200 8.3.4 STUN: Session Traversal Utilities for NAT
201 8.3.5 TURN: Traversal Using Relays around NAT
204 8.3.6 ICE: Interactive Connectivity Establishment
206 8.4 Session Border Controller
207 8.4.1 Enterprise SBC
209 8.4.2 Carrier SBC
210 8.5 Supporting Multiple-Carrier Connections
212 8.6 Mobility and Wireless Access
213 8.6.1 VoIP on Wireless LANs
Wi-Fi
213 8.6.2 Integration of Wi-Fi and Cellular Services
214 8.6.3 Packet Voice on Mobile Broadband: WiMAX, LTE
214 8.6.4 Radio over VoIP
215 IN SHORT: E&M Voice Signaling
216 9 Network Management for VoIP and UC 217 9.1 Starting Right
218 9.1.1 Acceptance Testing
219 9.1.2 Configuration Management and Governance
220 9.1.3 Privilege Setting
220 9.2 Continuous Monitoring and Management
221 9.2.1 NMS Software
222 9.2.2 Simple Network Management Protocol
223 9.2.3 Web Interface
224 9.2.4 Server Logging
224 9.2.5 Software Maintenance
225 9.2.6 Quality of Service
Experience Monitoring
225 9.2.7 Validate Adjustments and Optimization
226 9.3 Troubleshooting and Repair
226 9.3.1 Methods
226 9.3.2 Software Tools
228 9.3.3 Test Instruments
229 10 Cost Analysis and Payback Calculation 231 11 Examples of Hardware and Software 237 11.1 IP Phones
237 11.2 Gateways
240 11.3 Session Border Controllers
242 11.4 Call-Switching Servers
244 11.4.1 IP PBX
246 11.4.2 Conference Bridges
Controllers
248 11.4.3 Call Recorder
250 11.5 Hosted VoIP
UC Service
251 11.6 Management Systems
Workstations
252 12 Appendixes 253 12.1 Acronyms and Definitions
253 12.2 Reference Documents
268 12.2.1 RFCs
268 12.2.2 ITU Recommendations
272 12.2.3 Other Sources
272 12.3 Message and Error Codes
274 Index 277
1 1.2 The Digital PSTN
2 1.3 The Packet Revolution in Telephony
8 1.3.1 Summary of Packet Switching
9 1.3.2 Link Capacity: TDM versus Packets
11 1.3.3 VoIP and "The Cloud"
13 IN SHORT: Reading Network Drawings
14 2 Traditional Telephones Still Set Expectations 17 2.1 Availability: How the Bell System Ensured Service
18 2.2 Call Completion
19 2.3 Sound Quality: Encoding for Recognizable Voices
20 2.4 Low Latency
23 2.5 Call Setup Delays
24 2.6 Impairments Controlled: Echo, Singing, Distortion, Noise
25 3 From Circuits to Packets 27 3.1 Data and Signaling Preceded Voice
27 3.1.1 X.25 Packet Data Service
27 3.1.2 SS7: PSTN Signaling on Packets
28 3.1.3 ISDN
29 3.2 Putting Voice into Packets
30 3.2.1 Voice Encoding
31 3.2.2 Dicing and Splicing Voice Streams
32 3.2.3 The Latency Budget
33 4 Packet Transmission and Switching 37 4.1 The Physical Layer: Transmission
39 IN SHORT: The Endian Wars
40 4.2 Data Link Protocols
41 4.3 IP, the Network Protocol
43 4.4 Layer 4 Transport Protocols
47 4.4.1 Transmission Control Protocol
47 4.4.2 User Datagram Protocol
50 4.4.3 Stream Control Transmission Protocol
51 4.5 Higher Layer Processes
54 4.5.1 RTP
54 4.5.2 RTCP
57 4.5.3 Multiplexing RTP and RTCP on One UDP Port
58 4.5.4 RTP Mixers and Translators
59 4.5.5 Layered Encoding
60 4.5.6 Profiles for Audio and Video Conferences
60 4.5.7 Security via Encryption
61 IN SHORT: Public Key Infrastructure (PKI)
62 4.6 Saving Bandwidth
64 4.6.1 Voice Compression
64 4.6.2 Header Compression
66 4.6.3 Silence Suppression, VAD
67 4.6.4 Sub-Packet Multiplexing
69 4.6.5 Protocol and Codec Selection
70 4.7 Differences: Circuit versus Packet Switched
71 4.7.1 Power to the Desktop Phone
71 4.7.2 Phone as Computer and Computer as Phone
72 4.7.3 Length of a Phone Line
72 4.7.4 Scaling to Large Size
75 4.7.5 Software Ownership and Licenses
75 5 VoIP Signaling and Call Processing 77 5.1 What Packet Voice and UC Systems Share
78 5.2 Session Initiation Protocol (SIP)
80 5.2.1 SIP Architecture
81 5.2.2 SIP Messages
88 5.2.3 SIP Header Fields and Behaviors
94 5.3 Session Description Protocol
101 IN SHORT: ABNF
104 5.4 Media Gateway Control Protocol
107 5.4.1 MGW Functions
107 5.4.2 MGW Connection Model
110 5.4.3 Megaco Procedures
112 5.4.4 Megaco Details
115 5.4.5 Signaling Conversion
119 5.4.6 Voice Transcoding
119 5.5 H.323
120 5.5.1 H.323 Architecture
121 5.5.2 Gatekeeper
123 5.5.3 Gateway
126 5.5.4 Terminal
126 5.5.5 Multipoint Control Unit
127 5.5.6 Call Procedures
128 5.6 Directory Services
134 5.6.1 Domain Name Service (DNS)
134 5.6.2 ENUM
135 6 VoIP and Unified Communications Define the Future 139 6.1 Voice as Before, with Additions
139 6.2 Legacy Services to Keep and Improve with VoIP
140 6.2.1 Flexible Call Routing and 800 Numbers
141 6.2.2 Call on Hold
141 6.2.3 Call Transfer
142 6.2.4 Call Forwarding
142 6.2.5 Audio Conferencing
142 6.2.6 Video Conferencing
143 6.2.7 Local Number Portability
144 6.2.8 Direct Inward Dialing, Dialed Number Indication
144 6.2.9 Call
Message Waiting
145 6.2.10 Call Recording
146 6.2.11 Emergency Calling (E911)
146 6.2.12 Tracking IP Phone Locations for E911
150 6.3 Facsimile Transmission
153 6.3.1 Facsimile on the PSTN
153 6.3.2 Real-Time Fax over IP: Fax Relay or T.38
155 6.3.3 Store-and-Forward Fax Handling
160 6.3.4 IP Faxing over the PSTN
161 6.4 Phone Features Added with VoIP
UC
162 6.4.1 Presence
163 6.4.2 Forking
163 6.4.3 Voicemail1
4eMail
163 6.4.4 SMS Integration
164 6.4.5 Instant Messaging
165 6.4.6 Webinar Broadcasts
168 6.4.7 Telepresence
168 6.4.8 More UC Features to Consider
168 7 How VoIP and UC Impact the Network 171 7.1 Space, Power, and Cooling
171 7.2 Priority for Voice, Video, Fax Packets
172 7.3 Packets per Second
174 7.4 Bandwidth
174 7.5 Security Issues
175 7.5.1 Eavesdropping and vLAN Hopping
176 7.5.2 Access Controls for Users and Connections
176 7.5.3 Modems
177 7.5.4 DNS Cache Poisoning
177 IN SHORT: Earliest Instance of DNS Cache Poisoning
179 7.5.5 Toll Fraud
179 7.5.6 Pay-per-Call Scams
179 7.5.7 Vishing
180 7.5.8 SIP Scanning
SPIT
180 7.5.9 Opening the Firewall to Incoming Voice
181 7.6 First Migration Steps While Keeping Legacy Equipment
181 7.6.1 Circuit-Switched PBX
182 7.6.2 Digital Phones
182 7.6.3 Analog Phones and FX Service
183 7.6.4 Facsimile Machines
184 7.6.5 Modems
185 8 Interconnections to Global Services 187 8.1 Media Gateways
188 8.2 SIP Trunking
192 8.3 Operating VoIP Across Network Address Translation
196 8.3.1 Failures of SIP, SDP (Signaling)
199 8.3.2 Failures of RTP (Media)
199 8.3.3 Solutions
200 8.3.4 STUN: Session Traversal Utilities for NAT
201 8.3.5 TURN: Traversal Using Relays around NAT
204 8.3.6 ICE: Interactive Connectivity Establishment
206 8.4 Session Border Controller
207 8.4.1 Enterprise SBC
209 8.4.2 Carrier SBC
210 8.5 Supporting Multiple-Carrier Connections
212 8.6 Mobility and Wireless Access
213 8.6.1 VoIP on Wireless LANs
Wi-Fi
213 8.6.2 Integration of Wi-Fi and Cellular Services
214 8.6.3 Packet Voice on Mobile Broadband: WiMAX, LTE
214 8.6.4 Radio over VoIP
215 IN SHORT: E&M Voice Signaling
216 9 Network Management for VoIP and UC 217 9.1 Starting Right
218 9.1.1 Acceptance Testing
219 9.1.2 Configuration Management and Governance
220 9.1.3 Privilege Setting
220 9.2 Continuous Monitoring and Management
221 9.2.1 NMS Software
222 9.2.2 Simple Network Management Protocol
223 9.2.3 Web Interface
224 9.2.4 Server Logging
224 9.2.5 Software Maintenance
225 9.2.6 Quality of Service
Experience Monitoring
225 9.2.7 Validate Adjustments and Optimization
226 9.3 Troubleshooting and Repair
226 9.3.1 Methods
226 9.3.2 Software Tools
228 9.3.3 Test Instruments
229 10 Cost Analysis and Payback Calculation 231 11 Examples of Hardware and Software 237 11.1 IP Phones
237 11.2 Gateways
240 11.3 Session Border Controllers
242 11.4 Call-Switching Servers
244 11.4.1 IP PBX
246 11.4.2 Conference Bridges
Controllers
248 11.4.3 Call Recorder
250 11.5 Hosted VoIP
UC Service
251 11.6 Management Systems
Workstations
252 12 Appendixes 253 12.1 Acronyms and Definitions
253 12.2 Reference Documents
268 12.2.1 RFCs
268 12.2.2 ITU Recommendations
272 12.2.3 Other Sources
272 12.3 Message and Error Codes
274 Index 277
Preface xiii Acknowledgments xv 1 IP Technology Disrupts Voice Telephony 1 1.1 Introduction to the Public Switched Telephone Network
1 1.2 The Digital PSTN
2 1.3 The Packet Revolution in Telephony
8 1.3.1 Summary of Packet Switching
9 1.3.2 Link Capacity: TDM versus Packets
11 1.3.3 VoIP and "The Cloud"
13 IN SHORT: Reading Network Drawings
14 2 Traditional Telephones Still Set Expectations 17 2.1 Availability: How the Bell System Ensured Service
18 2.2 Call Completion
19 2.3 Sound Quality: Encoding for Recognizable Voices
20 2.4 Low Latency
23 2.5 Call Setup Delays
24 2.6 Impairments Controlled: Echo, Singing, Distortion, Noise
25 3 From Circuits to Packets 27 3.1 Data and Signaling Preceded Voice
27 3.1.1 X.25 Packet Data Service
27 3.1.2 SS7: PSTN Signaling on Packets
28 3.1.3 ISDN
29 3.2 Putting Voice into Packets
30 3.2.1 Voice Encoding
31 3.2.2 Dicing and Splicing Voice Streams
32 3.2.3 The Latency Budget
33 4 Packet Transmission and Switching 37 4.1 The Physical Layer: Transmission
39 IN SHORT: The Endian Wars
40 4.2 Data Link Protocols
41 4.3 IP, the Network Protocol
43 4.4 Layer 4 Transport Protocols
47 4.4.1 Transmission Control Protocol
47 4.4.2 User Datagram Protocol
50 4.4.3 Stream Control Transmission Protocol
51 4.5 Higher Layer Processes
54 4.5.1 RTP
54 4.5.2 RTCP
57 4.5.3 Multiplexing RTP and RTCP on One UDP Port
58 4.5.4 RTP Mixers and Translators
59 4.5.5 Layered Encoding
60 4.5.6 Profiles for Audio and Video Conferences
60 4.5.7 Security via Encryption
61 IN SHORT: Public Key Infrastructure (PKI)
62 4.6 Saving Bandwidth
64 4.6.1 Voice Compression
64 4.6.2 Header Compression
66 4.6.3 Silence Suppression, VAD
67 4.6.4 Sub-Packet Multiplexing
69 4.6.5 Protocol and Codec Selection
70 4.7 Differences: Circuit versus Packet Switched
71 4.7.1 Power to the Desktop Phone
71 4.7.2 Phone as Computer and Computer as Phone
72 4.7.3 Length of a Phone Line
72 4.7.4 Scaling to Large Size
75 4.7.5 Software Ownership and Licenses
75 5 VoIP Signaling and Call Processing 77 5.1 What Packet Voice and UC Systems Share
78 5.2 Session Initiation Protocol (SIP)
80 5.2.1 SIP Architecture
81 5.2.2 SIP Messages
88 5.2.3 SIP Header Fields and Behaviors
94 5.3 Session Description Protocol
101 IN SHORT: ABNF
104 5.4 Media Gateway Control Protocol
107 5.4.1 MGW Functions
107 5.4.2 MGW Connection Model
110 5.4.3 Megaco Procedures
112 5.4.4 Megaco Details
115 5.4.5 Signaling Conversion
119 5.4.6 Voice Transcoding
119 5.5 H.323
120 5.5.1 H.323 Architecture
121 5.5.2 Gatekeeper
123 5.5.3 Gateway
126 5.5.4 Terminal
126 5.5.5 Multipoint Control Unit
127 5.5.6 Call Procedures
128 5.6 Directory Services
134 5.6.1 Domain Name Service (DNS)
134 5.6.2 ENUM
135 6 VoIP and Unified Communications Define the Future 139 6.1 Voice as Before, with Additions
139 6.2 Legacy Services to Keep and Improve with VoIP
140 6.2.1 Flexible Call Routing and 800 Numbers
141 6.2.2 Call on Hold
141 6.2.3 Call Transfer
142 6.2.4 Call Forwarding
142 6.2.5 Audio Conferencing
142 6.2.6 Video Conferencing
143 6.2.7 Local Number Portability
144 6.2.8 Direct Inward Dialing, Dialed Number Indication
144 6.2.9 Call
Message Waiting
145 6.2.10 Call Recording
146 6.2.11 Emergency Calling (E911)
146 6.2.12 Tracking IP Phone Locations for E911
150 6.3 Facsimile Transmission
153 6.3.1 Facsimile on the PSTN
153 6.3.2 Real-Time Fax over IP: Fax Relay or T.38
155 6.3.3 Store-and-Forward Fax Handling
160 6.3.4 IP Faxing over the PSTN
161 6.4 Phone Features Added with VoIP
UC
162 6.4.1 Presence
163 6.4.2 Forking
163 6.4.3 Voicemail1
4eMail
163 6.4.4 SMS Integration
164 6.4.5 Instant Messaging
165 6.4.6 Webinar Broadcasts
168 6.4.7 Telepresence
168 6.4.8 More UC Features to Consider
168 7 How VoIP and UC Impact the Network 171 7.1 Space, Power, and Cooling
171 7.2 Priority for Voice, Video, Fax Packets
172 7.3 Packets per Second
174 7.4 Bandwidth
174 7.5 Security Issues
175 7.5.1 Eavesdropping and vLAN Hopping
176 7.5.2 Access Controls for Users and Connections
176 7.5.3 Modems
177 7.5.4 DNS Cache Poisoning
177 IN SHORT: Earliest Instance of DNS Cache Poisoning
179 7.5.5 Toll Fraud
179 7.5.6 Pay-per-Call Scams
179 7.5.7 Vishing
180 7.5.8 SIP Scanning
SPIT
180 7.5.9 Opening the Firewall to Incoming Voice
181 7.6 First Migration Steps While Keeping Legacy Equipment
181 7.6.1 Circuit-Switched PBX
182 7.6.2 Digital Phones
182 7.6.3 Analog Phones and FX Service
183 7.6.4 Facsimile Machines
184 7.6.5 Modems
185 8 Interconnections to Global Services 187 8.1 Media Gateways
188 8.2 SIP Trunking
192 8.3 Operating VoIP Across Network Address Translation
196 8.3.1 Failures of SIP, SDP (Signaling)
199 8.3.2 Failures of RTP (Media)
199 8.3.3 Solutions
200 8.3.4 STUN: Session Traversal Utilities for NAT
201 8.3.5 TURN: Traversal Using Relays around NAT
204 8.3.6 ICE: Interactive Connectivity Establishment
206 8.4 Session Border Controller
207 8.4.1 Enterprise SBC
209 8.4.2 Carrier SBC
210 8.5 Supporting Multiple-Carrier Connections
212 8.6 Mobility and Wireless Access
213 8.6.1 VoIP on Wireless LANs
Wi-Fi
213 8.6.2 Integration of Wi-Fi and Cellular Services
214 8.6.3 Packet Voice on Mobile Broadband: WiMAX, LTE
214 8.6.4 Radio over VoIP
215 IN SHORT: E&M Voice Signaling
216 9 Network Management for VoIP and UC 217 9.1 Starting Right
218 9.1.1 Acceptance Testing
219 9.1.2 Configuration Management and Governance
220 9.1.3 Privilege Setting
220 9.2 Continuous Monitoring and Management
221 9.2.1 NMS Software
222 9.2.2 Simple Network Management Protocol
223 9.2.3 Web Interface
224 9.2.4 Server Logging
224 9.2.5 Software Maintenance
225 9.2.6 Quality of Service
Experience Monitoring
225 9.2.7 Validate Adjustments and Optimization
226 9.3 Troubleshooting and Repair
226 9.3.1 Methods
226 9.3.2 Software Tools
228 9.3.3 Test Instruments
229 10 Cost Analysis and Payback Calculation 231 11 Examples of Hardware and Software 237 11.1 IP Phones
237 11.2 Gateways
240 11.3 Session Border Controllers
242 11.4 Call-Switching Servers
244 11.4.1 IP PBX
246 11.4.2 Conference Bridges
Controllers
248 11.4.3 Call Recorder
250 11.5 Hosted VoIP
UC Service
251 11.6 Management Systems
Workstations
252 12 Appendixes 253 12.1 Acronyms and Definitions
253 12.2 Reference Documents
268 12.2.1 RFCs
268 12.2.2 ITU Recommendations
272 12.2.3 Other Sources
272 12.3 Message and Error Codes
274 Index 277
1 1.2 The Digital PSTN
2 1.3 The Packet Revolution in Telephony
8 1.3.1 Summary of Packet Switching
9 1.3.2 Link Capacity: TDM versus Packets
11 1.3.3 VoIP and "The Cloud"
13 IN SHORT: Reading Network Drawings
14 2 Traditional Telephones Still Set Expectations 17 2.1 Availability: How the Bell System Ensured Service
18 2.2 Call Completion
19 2.3 Sound Quality: Encoding for Recognizable Voices
20 2.4 Low Latency
23 2.5 Call Setup Delays
24 2.6 Impairments Controlled: Echo, Singing, Distortion, Noise
25 3 From Circuits to Packets 27 3.1 Data and Signaling Preceded Voice
27 3.1.1 X.25 Packet Data Service
27 3.1.2 SS7: PSTN Signaling on Packets
28 3.1.3 ISDN
29 3.2 Putting Voice into Packets
30 3.2.1 Voice Encoding
31 3.2.2 Dicing and Splicing Voice Streams
32 3.2.3 The Latency Budget
33 4 Packet Transmission and Switching 37 4.1 The Physical Layer: Transmission
39 IN SHORT: The Endian Wars
40 4.2 Data Link Protocols
41 4.3 IP, the Network Protocol
43 4.4 Layer 4 Transport Protocols
47 4.4.1 Transmission Control Protocol
47 4.4.2 User Datagram Protocol
50 4.4.3 Stream Control Transmission Protocol
51 4.5 Higher Layer Processes
54 4.5.1 RTP
54 4.5.2 RTCP
57 4.5.3 Multiplexing RTP and RTCP on One UDP Port
58 4.5.4 RTP Mixers and Translators
59 4.5.5 Layered Encoding
60 4.5.6 Profiles for Audio and Video Conferences
60 4.5.7 Security via Encryption
61 IN SHORT: Public Key Infrastructure (PKI)
62 4.6 Saving Bandwidth
64 4.6.1 Voice Compression
64 4.6.2 Header Compression
66 4.6.3 Silence Suppression, VAD
67 4.6.4 Sub-Packet Multiplexing
69 4.6.5 Protocol and Codec Selection
70 4.7 Differences: Circuit versus Packet Switched
71 4.7.1 Power to the Desktop Phone
71 4.7.2 Phone as Computer and Computer as Phone
72 4.7.3 Length of a Phone Line
72 4.7.4 Scaling to Large Size
75 4.7.5 Software Ownership and Licenses
75 5 VoIP Signaling and Call Processing 77 5.1 What Packet Voice and UC Systems Share
78 5.2 Session Initiation Protocol (SIP)
80 5.2.1 SIP Architecture
81 5.2.2 SIP Messages
88 5.2.3 SIP Header Fields and Behaviors
94 5.3 Session Description Protocol
101 IN SHORT: ABNF
104 5.4 Media Gateway Control Protocol
107 5.4.1 MGW Functions
107 5.4.2 MGW Connection Model
110 5.4.3 Megaco Procedures
112 5.4.4 Megaco Details
115 5.4.5 Signaling Conversion
119 5.4.6 Voice Transcoding
119 5.5 H.323
120 5.5.1 H.323 Architecture
121 5.5.2 Gatekeeper
123 5.5.3 Gateway
126 5.5.4 Terminal
126 5.5.5 Multipoint Control Unit
127 5.5.6 Call Procedures
128 5.6 Directory Services
134 5.6.1 Domain Name Service (DNS)
134 5.6.2 ENUM
135 6 VoIP and Unified Communications Define the Future 139 6.1 Voice as Before, with Additions
139 6.2 Legacy Services to Keep and Improve with VoIP
140 6.2.1 Flexible Call Routing and 800 Numbers
141 6.2.2 Call on Hold
141 6.2.3 Call Transfer
142 6.2.4 Call Forwarding
142 6.2.5 Audio Conferencing
142 6.2.6 Video Conferencing
143 6.2.7 Local Number Portability
144 6.2.8 Direct Inward Dialing, Dialed Number Indication
144 6.2.9 Call
Message Waiting
145 6.2.10 Call Recording
146 6.2.11 Emergency Calling (E911)
146 6.2.12 Tracking IP Phone Locations for E911
150 6.3 Facsimile Transmission
153 6.3.1 Facsimile on the PSTN
153 6.3.2 Real-Time Fax over IP: Fax Relay or T.38
155 6.3.3 Store-and-Forward Fax Handling
160 6.3.4 IP Faxing over the PSTN
161 6.4 Phone Features Added with VoIP
UC
162 6.4.1 Presence
163 6.4.2 Forking
163 6.4.3 Voicemail1
4eMail
163 6.4.4 SMS Integration
164 6.4.5 Instant Messaging
165 6.4.6 Webinar Broadcasts
168 6.4.7 Telepresence
168 6.4.8 More UC Features to Consider
168 7 How VoIP and UC Impact the Network 171 7.1 Space, Power, and Cooling
171 7.2 Priority for Voice, Video, Fax Packets
172 7.3 Packets per Second
174 7.4 Bandwidth
174 7.5 Security Issues
175 7.5.1 Eavesdropping and vLAN Hopping
176 7.5.2 Access Controls for Users and Connections
176 7.5.3 Modems
177 7.5.4 DNS Cache Poisoning
177 IN SHORT: Earliest Instance of DNS Cache Poisoning
179 7.5.5 Toll Fraud
179 7.5.6 Pay-per-Call Scams
179 7.5.7 Vishing
180 7.5.8 SIP Scanning
SPIT
180 7.5.9 Opening the Firewall to Incoming Voice
181 7.6 First Migration Steps While Keeping Legacy Equipment
181 7.6.1 Circuit-Switched PBX
182 7.6.2 Digital Phones
182 7.6.3 Analog Phones and FX Service
183 7.6.4 Facsimile Machines
184 7.6.5 Modems
185 8 Interconnections to Global Services 187 8.1 Media Gateways
188 8.2 SIP Trunking
192 8.3 Operating VoIP Across Network Address Translation
196 8.3.1 Failures of SIP, SDP (Signaling)
199 8.3.2 Failures of RTP (Media)
199 8.3.3 Solutions
200 8.3.4 STUN: Session Traversal Utilities for NAT
201 8.3.5 TURN: Traversal Using Relays around NAT
204 8.3.6 ICE: Interactive Connectivity Establishment
206 8.4 Session Border Controller
207 8.4.1 Enterprise SBC
209 8.4.2 Carrier SBC
210 8.5 Supporting Multiple-Carrier Connections
212 8.6 Mobility and Wireless Access
213 8.6.1 VoIP on Wireless LANs
Wi-Fi
213 8.6.2 Integration of Wi-Fi and Cellular Services
214 8.6.3 Packet Voice on Mobile Broadband: WiMAX, LTE
214 8.6.4 Radio over VoIP
215 IN SHORT: E&M Voice Signaling
216 9 Network Management for VoIP and UC 217 9.1 Starting Right
218 9.1.1 Acceptance Testing
219 9.1.2 Configuration Management and Governance
220 9.1.3 Privilege Setting
220 9.2 Continuous Monitoring and Management
221 9.2.1 NMS Software
222 9.2.2 Simple Network Management Protocol
223 9.2.3 Web Interface
224 9.2.4 Server Logging
224 9.2.5 Software Maintenance
225 9.2.6 Quality of Service
Experience Monitoring
225 9.2.7 Validate Adjustments and Optimization
226 9.3 Troubleshooting and Repair
226 9.3.1 Methods
226 9.3.2 Software Tools
228 9.3.3 Test Instruments
229 10 Cost Analysis and Payback Calculation 231 11 Examples of Hardware and Software 237 11.1 IP Phones
237 11.2 Gateways
240 11.3 Session Border Controllers
242 11.4 Call-Switching Servers
244 11.4.1 IP PBX
246 11.4.2 Conference Bridges
Controllers
248 11.4.3 Call Recorder
250 11.5 Hosted VoIP
UC Service
251 11.6 Management Systems
Workstations
252 12 Appendixes 253 12.1 Acronyms and Definitions
253 12.2 Reference Documents
268 12.2.1 RFCs
268 12.2.2 ITU Recommendations
272 12.2.3 Other Sources
272 12.3 Message and Error Codes
274 Index 277