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Emerging Technology Development for Multimedia Communications John Pang Yu Ph. D. Managing Director The Emerging Technology Development for Multimedia Communications John Pang Yu Ph. D. Managing Director The Emerging Technologies Cooperative, Inc. Menlo Park, California USA National Taipei University of Technology, Taipei, Taiwan John P. Yu November 13, 2006 Slide 1 of 48 Confidential *

Table of Contents (Continued) • • DCo. IP Device and System Developers Existing and Table of Contents (Continued) • • DCo. IP Device and System Developers Existing and Proposed Standards Quality of Services Technical Advancements DCo. IP Market Trends DCo. IP Challenges References John P. Yu November 13, 2006 Slide 3 of 48 Confidential *

Introduction To Conventional Communication Technological Concepts • • Transmission Line Loss, Echoes, Delay, Gain Introduction To Conventional Communication Technological Concepts • • Transmission Line Loss, Echoes, Delay, Gain Insertion Loss, Impedance Matching, Crosstalk, Return Loss Signal Bandwidth and Noise Measurement Differential Gain and Differential Phase (non-linearity of a two-port system) • X. 25 Seven Layer Protocol: Application, Presentation, Session, Transport, Network, Data Link and Physical • Modulation: Amplitude-Modulated Signals: Double-Sideband with Transmitter Carrier; Double-Sideband with Suppressed Carrier; Single-Sideband with Transmitter Carrier. John P. Yu November 13, 2006 Slide 4 of 48 Confidential *

Introduction To Conventional Communication Technological Concepts (Continued) • Modulation: Amplitude-Modulated Signals: Vestigial-Sideband with Transmitter Introduction To Conventional Communication Technological Concepts (Continued) • Modulation: Amplitude-Modulated Signals: Vestigial-Sideband with Transmitter Carrier (TV RF Signal) Angle-Modulated Signals; Pulse Amplitude Modulation; Pulse Duration Modulation; Pulse Code Modulation; Frequency. Modulated Signals; Digital Subscriber Line (DSL) • Multiplexing: Space Division Multiplex (SDM); Frequency Division Multiplex; Time-Domain Multiplex (TDM); Wavelength Division Multiplex (WDM); Digital Subscriber Loop (DSL) Access Multiplex (DSLAMs) John P. Yu November 13, 2006 Slide 5 of 48 Confidential *

Some Data Communication Interface Standards • Committee Consulting International Telephone and Telegraph (CCITT) • Some Data Communication Interface Standards • Committee Consulting International Telephone and Telegraph (CCITT) • Electronic Industrial Association (EIA): RS-232 -C, RS-422, RS-485 • PSTN, ISDN, DSLAM, T 1 (DS-1: 1. 544 Mbps), E 1 (2. 048 Mbps), OC-1 (STS-1: 51. 84 Mbps) • T. 38: Voice, Data and Fax over Different Telephone Lines • Loop Start Interface (LSI: analog PSTN) John P. Yu November 13, 2006 Slide 6 of 48 Confidential *

Interactive Video Display System • A Bi-Directional Interactive Data Communication Systems Via MODEM and Interactive Video Display System • A Bi-Directional Interactive Data Communication Systems Via MODEM and Telephone Line • Image Plans and video Graphic Mode • Texts and Graphics Mixed Mode • Video Graphics and Texts Display Processors in A Digital Format • Information Retrieval Between Video Display Terminal and Terminal • Information Retrieval Between Video Display Terminal and Database (Information Provider) • A Bi-Directional Interactive Data Communication System Via RF MODEM and Cable John P. Yu November 13, 2006 Slide 7 of 48 Confidential *

Worldwide Video Standards NTSC PAL SECAM Line / Field 525 / 60 625 / Worldwide Video Standards NTSC PAL SECAM Line / Field 525 / 60 625 / 50 H. Frequency 15. 734 KHz 15. 625 KHz V. Frequency Color Subcarrier 59. 94 Hz 3. 579545 MHz 50 Hz 4. 433618 MHz Sound Carrier Video Bandwidth (Y) 4. 5 MHz (FM) 4. 2 MHZ 6. 0 MHz (FM) 5. 5 MHz Video Component R G B Or Y I Q or Y B-Y R-Y 2 : 1 30 4 : 3 R G B Or YUV 819 / 50 “E” Mono 625 / 50 “L” Color 20. 745 KHz “E” 15. 625 KHZ “L” 50 Hz “E” & “L” 4. 40625 MHz OR 4. 25000 MHz OB 6. 5 MHz (AM) “L” 10 MHz “E” 6. 0 MHz “L” R G B Or YUV 2 : 1 25 4 : 3 Interlaced Frames / Second Aspect Ratio John P. Yu November 13, 2006 Slide 8 of 48 Confidential *

Proposed HDTV Standards Japan USA Europe Line / Field 1125 / 60 1050 / Proposed HDTV Standards Japan USA Europe Line / Field 1125 / 60 1050 / 59. 94 1152 / 50 H. Frequency V. Frequency 33. 7495 KHz 60 Hz 31. 468 KHz 59. 94 Hz 50 Hz 31. 25 KHz Video Bandwidth (Y) 30 MHz 40 MHz Chrominance BW (B-Y) Chrominance BW (R-Y) 15 MHz 20 MHz Interlaced Frames / Second Aspect Ratio 2 : 1 30 16 : 9 John P. Yu November 13, 2006 Slide 9 of 48 Confidential * 2 : 1 25 16 : 9

Telecommunications Digital Transmission Hierarch Highlights Digital Signal DS-0 Optical Transmit DS-1 DS-2 DS-3 OC-1 Telecommunications Digital Transmission Hierarch Highlights Digital Signal DS-0 Optical Transmit DS-1 DS-2 DS-3 OC-1 OC-3 Electrical Transmit E 0 /J 0 Line Bit Rate 64 Kbps T 1 /J 1 E 1 T 2 E 3 T 3 STS-1 E 4 STS-3 1. 544 Mbps 1. 536 Mbps 24 2. 048 32 6. 312 96 8. 448 128 34. 368 512 44. 736 672 51. 84 50 672 139. 264 2048 155. 52 150 2016 274. 176 4032 466. 56 451 6048 622. 08 601 8064 1. 244 Gbps 1. 20 Gbps 16128 4. 976 4. 81 64512 13. 271 172032 39. 813 516096 DS-4 OC-9 OC-12 OC-24 OC-96 OC-256 OC-768 John P. Yu November 13, 2006 STS-9 STS-12 STS-24 STS-96 Effective # DS 0 s in Data Rate Payload 64 Kbps 1 Slide 10 of 48 Confidential * #DS 1 s in Payload #DS 3 s Others in Payload SDH Level 1 4 28 28 1 1 84 168 252 336 672 2688 7168 3 6 9 12 24 96 256 STM-1 4 OC-3 STM-4 STM-8 STM-32

Introduction to Digital Contents over IP John P. Yu November 13, 2006 Slide 11 Introduction to Digital Contents over IP John P. Yu November 13, 2006 Slide 11 of 48 Confidential *

DCo. IP Network Topology Gatekeeper IP Network Connection PSTN to Vo. IP to PSTN DCo. IP Network Topology Gatekeeper IP Network Connection PSTN to Vo. IP to PSTN Gateway Phone Line PSTN Phone Line Equipment to Bridge the Circuit-Switched Network and Packet-Switched Network John P. Yu November 13, 2006 Slide 12 of 48 Confidential *

DCo. IP Network Topology Router H. 323 End. Points H. 323 MCS with gateway DCo. IP Network Topology Router H. 323 End. Points H. 323 MCS with gateway H. 323 End. Point POTS ISDN H. 323 End. Points Telephone Firewall & H. 323 proxy H. 323 Gatekeeper John P. Yu November 13, 2006 Circuit Switched Network INTERNET Slide 13 of 48 Confidential * H. 323 MCS with gateway H. 323 End. Point

DCo. IP Network Topology H. 323 ITU Terminals Circuit Switched Network H. 320 ISDN DCo. IP Network Topology H. 323 ITU Terminals Circuit Switched Network H. 320 ISDN H. 324 PSTN H. 323 Internet H. 323 Terminals Gateway H. 323 Zone H. 323 Gate. Keeper MCU H. 323 Terminals Major Entities in an H. 32 X Environment: H. 323 Terminals, Gateways, Gatekeepers and MCUs. John P. Yu November 13, 2006 Slide 14 of 48 Confidential *

Circuit-Switched Network John P. Yu November 13, 2006 Slide 15 of 48 Confidential * Circuit-Switched Network John P. Yu November 13, 2006 Slide 15 of 48 Confidential *

Packet-Switched Network John P. Yu November 13, 2006 Slide 16 of 48 Confidential * Packet-Switched Network John P. Yu November 13, 2006 Slide 16 of 48 Confidential *

Internet Protocol Version 6 (IPv 6) John P. Yu November 13, 2006 Slide 17 Internet Protocol Version 6 (IPv 6) John P. Yu November 13, 2006 Slide 17 of 48 Confidential *

IPv 4 vs IPv 6 • Address space increased from 32 bits to 128 IPv 4 vs IPv 6 • Address space increased from 32 bits to 128 – IPv 4 has about 4 Billion addresses (US, Europe, rest of the world) – IPv 6 has about 2^128 = 3. 4 X 10 ^ 38 addresses • Approx. 665 X 10 ^21 addresses per sq. m of the earth surface • IPv 6 has built in IP security (IPsecurity is part of IPv 6) • IPv 6 has fixed length header. – Optimized for hardware implementation • IPv 6 has improved support for Qo. S, Multicast and Mobile IP • IPv 6 has support for domestic appliances • Government (DOD 2008), University and Industry lead initiatives John P. Yu November 13, 2006 Slide 18 of 48 Confidential *

IPv 6 Partners John P. Yu November 13, 2006 Slide 19 of 48 Confidential IPv 6 Partners John P. Yu November 13, 2006 Slide 19 of 48 Confidential *

IPv 6 Partners (Continued) John P. Yu November 13, 2006 Slide 20 of 48 IPv 6 Partners (Continued) John P. Yu November 13, 2006 Slide 20 of 48 Confidential *

IPv 6 Partners (Continued) John P. Yu November 13, 2006 Slide 21 of 48 IPv 6 Partners (Continued) John P. Yu November 13, 2006 Slide 21 of 48 Confidential *

Major System Components John P. Yu November 13, 2006 Slide 22 of 48 Confidential Major System Components John P. Yu November 13, 2006 Slide 22 of 48 Confidential *

Major System Components (Continued) John P. Yu November 13, 2006 Slide 23 of 48 Major System Components (Continued) John P. Yu November 13, 2006 Slide 23 of 48 Confidential *

Major System Components (Continued) John P. Yu November 13, 2006 Slide 24 of 48 Major System Components (Continued) John P. Yu November 13, 2006 Slide 24 of 48 Confidential *

Major System Components (Continued) John P. Yu November 13, 2006 Slide 25 of 48 Major System Components (Continued) John P. Yu November 13, 2006 Slide 25 of 48 Confidential *

DCo. IP Device and System Developers John P. Yu November 13, 2006 Slide 26 DCo. IP Device and System Developers John P. Yu November 13, 2006 Slide 26 of 48 Confidential *

DCo. IP Device and System Developers (Continued) John P. Yu November 13, 2006 Slide DCo. IP Device and System Developers (Continued) John P. Yu November 13, 2006 Slide 27 of 48 Confidential *

DCo. IP Device and System Developers (Continued) John P. Yu November 13, 2006 Slide DCo. IP Device and System Developers (Continued) John P. Yu November 13, 2006 Slide 28 of 48 Confidential *

DCo. IP Device and System Developers (Continued) John P. Yu November 13, 2006 Slide DCo. IP Device and System Developers (Continued) John P. Yu November 13, 2006 Slide 29 of 48 Confidential *

Existing and Proposed Standards John P. Yu November 13, 2006 Slide 30 of 48 Existing and Proposed Standards John P. Yu November 13, 2006 Slide 30 of 48 Confidential *

Video Compression Techniques Type Compression (CODEC) Rate Formats Application H. 261 p x 64 Video Compression Techniques Type Compression (CODEC) Rate Formats Application H. 261 p x 64 Kbit/s (p is in the range 1 -30). QCIF, CIF PSTN, PSDN H. 263 20 -30 kbps and above QCIF, CIF SQCIF, 4 CIF 16 CIF. SQCIF PSTN, PSDN, Video Conferencing, Video Telephony H. 264 Less than 1 Mb/s MPEG-4 AVC Internet Protocolbased broadcastquality video MPEG 2 IS-13818 4 Mbps or higher Progressive coding broadcast quality video MPEG 4 'ISO/IEC 14496' Less than 1. 15 Mb/s MPEG-4 Digital television, Interactive graphics applications, Interactive multimedia John P. Yu November 13, 2006 Slide 31 of 48 Confidential *

Existing and Proposed Standards (Continued) H. 323 Protocol Stack ¨ H. 323 Entities include Existing and Proposed Standards (Continued) H. 323 Protocol Stack ¨ H. 323 Entities include Terminals, Gateways, Gatekeepers and Multipoint Control Unit; APIs; Object and Source Code; Version 2 to Include H. 450 and H. 235. ¨ H. 323 Version 2 Provides the Following: Compression Schemes, Real Security Measures, Improved Signaling, Qo. S, and Improved Resource Management. ¨ H. 323 Enlists a Number of Other Protocols for Interoperability as Follows: ¨ ¨ ¨ ¨ ¨ G. 711, G. 722, G. 728, G. 723. 1, G. 729 for Codec at the Presentation Layer (OSI model) Real-Time Transport Protocol (RTP) at the Transport Layer Resource Reservation Protocol (RSVP) at the Network Layer Real-Time Transport Control Protocol (RTCP) H. 225 for Standard Call Setup Sequences / Packet Synchronization H. 245 Specifies Messages for Opening and Closing Channels for Media Streams, and Other Commands, Requests and Indications at the Session Layer H. 261 for Video Codec for Audiovisual at P x 64 kbps H. 263 for a New Codec for Video Over PSTN T. 120 Series of Multimedia Communications Protocol T. 38 for Real-Time Fax; Procedures for Real Time Group 3 Facsimile Communication Between Terminals Using IP Networks John P. Yu November 13, 2006 Slide 32 of 48 Confidential *

IP Protocols H. 323, SIP, MGCP, Megaco/H. 248 • H. 323 – IP communications IP Protocols H. 323, SIP, MGCP, Megaco/H. 248 • H. 323 – IP communications protocol for real-time voice and video over IP. – Includes core protocol and gatekeeper toolkits. – International Telecommunications Union (ITU) recommendation for audio, video, and data communications across IP-based networks. • SIP (Session Initiation Protocol) – Signaling protocol for establishing real-time calls and conferences over IP networks. – SIP is an IETF (Internet Engineering Task Force) Protocol. • MGCP (Media Gateway Control Protocol) – A complementary IETF protocol to H. 323 and SIP – Defines the communication procedures for a Media Gateway Controller to provide instructions and to gather information from Media Gateways • Megaco/H. 248 (Media Gateway Control) – Similar to MGCP, jointly defined by the IETF and ITU-T SG-16 – Gradually replacing MGCP – Megaco renamed GCP (Gateway Control Protocol) -- RFC 3525 John P. Yu November 13, 2006 Slide 33 of 48 Confidential *

RTP / RTCP Real-Time Transport Protocol (RTP) • Provides end-to-end delivery services of real-time RTP / RTCP Real-Time Transport Protocol (RTP) • Provides end-to-end delivery services of real-time Audio (G. 711, G. 723. 1, G. 728, etc. ) and Video (H. 261, H. 263), • Data is transported via the user datagram protocol (UDP). • RTP provides payload-type identification, sequence numbering, time stamping, and delivery monitoring. • UDP provides multiplexing and checksum services. • RTP can be used with other transport protocols. Real-Time Transport Control Protocol (RTCP) • Counterpart of RTP that provides control services • Primary function of RTCP is to provide feedback on the quality of the data distribution – RTCP-XR • Carries transport-level identifier for an RTP source – Used by receivers to synchronize audio and video. John P. Yu November 13, 2006 Slide 34 of 48 Confidential *

Existing and Proposed Standards (Continued) ITU-T Speech Coding Standards ¨ ¨ ¨ Description G. Existing and Proposed Standards (Continued) ITU-T Speech Coding Standards ¨ ¨ ¨ Description G. 711 G. 722 G. 726 G. 727 G. 728 64 kbps PCM (Both A-Law and u-Law) (1988) Wideband Vocoder Operating at 64, 56, or 48 kbps ADPCM Vocoder Recommendation That Folds G. 721 and G. 723 Embedded ADPCM Operating at 40, 32, 24, or 16 kbps 16 -kbps Low-Delay Code-Excited Linear Prediction Vocoder (LD-CELP) ¨ G. 729 8 -kbps Conjugate-Structure Algebraic-Code-Excited Linear Prediction (CS-ACELP) ¨ G. 729 A Annex A: Reduced Complexity 8 kbps CS-ACELP Speech Code ¨ G. 723. 1 Low-Bit-Rate Vocoder for Multimedia Communications Operating at 6. 3 and 5. 3 kbps (1996) John P. Yu November 13, 2006 Slide 35 of 48 Confidential *

Quality of Services Qo. S Technical Constraints ¨ Latency is the Most Technical Problem Quality of Services Qo. S Technical Constraints ¨ Latency is the Most Technical Problem Over Internet Telephony: by Delay, Delay Variance (or Jitter), Asymmetrical Delay, and Unpredictable Delay ¨ Twenty (20) ms Coast-to-Coast Delay in the U. S. : Mostly Noticeable ¨ Fifty (50) ms Delay is Noticeable ¨ 250 ms Delay by the Satellites - Conversation Becomes Difficult ¨ 350 ms Delay Over the Public Internet From Encoding and Packetizing at Both Ends of the Call ¨ Standard Half-Duplex Sound Card: Amateur Radio Conversation Quality ¨ Latency is Dependent on Lost a Packet (30 ms) or Packets, Packet Size, Buffer Size, Speaker Behavior Parameter, Protocol Application, Frame Delay, Speech Process Delay, Bridging Delay, PC Too Overloaded to Run Vocoder, and Protocol Limitations John P. Yu November 13, 2006 Slide 36 of 48 Confidential *

Quality of Services (Continued) Performance Evaluations: ¨ Delay 200 Milliseconds From a Private IP Quality of Services (Continued) Performance Evaluations: ¨ Delay 200 Milliseconds From a Private IP Network With Good Encoding and Excellent DSP Technologies ¨ Laboratory Demonstrations to Analyze Voice Quality With 100 ms, 150 ms, 200 ms, and 250 ms Latency With the Following Setups: 1. Workstation-to-Workstation Using the Gatekeeper 2. Workstation-to-Phone Using the Cisco 3620 as a H. 323 Gateway 3. Phone-to-Phone Using Netrix 2210 and Cisco 3620 for Calls Connections Through IP Network John P. Yu November 13, 2006 Slide 37 of 48 Confidential *

Effect of Delay on Voice Quality > 25 ms Echo Cancellation Required N T Effect of Delay on Voice Quality > 25 ms Echo Cancellation Required N T PS <150 ms (with echo cancellation): acceptable 150 -400 ms: acceptable if delay expected John P. Yu November 13, 2006 Slide 38 of 48 Confidential *

Technical Advancements ¨ Resource Reser. Vation Protocol (RSVP) - It is a Receiver-Driven and Technical Advancements ¨ Resource Reser. Vation Protocol (RSVP) - It is a Receiver-Driven and up to the Receiver to Select Which Source to Receive and Amount of Bandwidth to be Reserved or Paid for ¨ Parallel IP Networks - Different Bandwidth Allocations for Data and Multimedia by Virtual or Physical ¨ Packet Networks Take on Circuit Networks ¨ Parallel or Overlay Networks are Being Built to Support Real-time Multimedia Traffic ¨ Today’s DSP Delivers More Than 15 Times the Price/Performance of Its Predecessors Ten Years Ago, Providing 100 MIPS or Faster for Voice and Video Compression and Thus Reducing Latency John P. Yu November 13, 2006 Slide 39 of 48 Confidential *

Vo. IP Market Trends Source: The Yankee Group John P. Yu November 13, 2006 Vo. IP Market Trends Source: The Yankee Group John P. Yu November 13, 2006 Voice vs IP Growth Slide 40 of 48 Confidential *

Vo. IP Market Trends Voice Minutes Over IP by Year Source: The Yankee Group, Vo. IP Market Trends Voice Minutes Over IP by Year Source: The Yankee Group, 1997 John P. Yu November 13, 2006 Slide 41 of 48 Confidential *

DCo. IP Market Trends VSAN: Voice Services Over Alternate Networks How Much Voice Traffic DCo. IP Market Trends VSAN: Voice Services Over Alternate Networks How Much Voice Traffic Will Migrate to VSANs Over the Next Five Years ? Source: The Yankee Group John P. Yu November 13, 2006 Slide 42 of 48 Confidential *

DCo. IP Market Trends User Perceptions of Voice over the Internet Source: The Yankee DCo. IP Market Trends User Perceptions of Voice over the Internet Source: The Yankee Group John P. Yu November 13, 2006 Slide 43 of 48 Confidential *

DCo. IP Market Trends ¨ More IP-Based Services - Proxy Services for H. 323 DCo. IP Market Trends ¨ More IP-Based Services - Proxy Services for H. 323 ¨ More Security Features - Encryption for Conference Security, IP Security (IETF Standard) ¨ More Network Interfaces - ATM, Frame Relay, Direct Dial IP Over ISDN ¨ Vo. IP Market Potential - $560 Million for IT User in 1999, 34 % of Telephone Calls Carried on Packet Networks by 2005 ¨ EURO IP Telephone Market Worth $3. 9 Billion by 2003 Per Dataquest ¨ Asia’s E-Commerce: Jumping to $40 Billion in 2003; Jump 100 % Annually ¨ The Vo. IP Market Revenues at $290 Million in 1999 and Predict Only $1. 8 Billion in Sales in 2003 ¨ U. S. Unified Messaging Market for Business: $175 Million (1997 - 1998) and Lucent had 24 % Market Share Per Frost & Sullivan’s Report ¨ Real Value of Vo. IP is Its Ability to Integrate Voice and Data for Multimedia Applications, Not Just A Low Cost Alternate to PSTN John P. Yu November 13, 2006 Slide 44 of 48 Confidential *

DCo. IP Challenges ¨ Getting Telcos up to Speed With New Technology and Willingness DCo. IP Challenges ¨ Getting Telcos up to Speed With New Technology and Willingness to Stick Around the Existing PBXs and Vo. IP ¨ Setting H. 323, H. 100 / H. 110 Standards ¨ Quality of Services (Qo. S) ¨ Latency Problem (Delay) ¨ Advanced Voice Compression Techniques ¨ According to the Yankee Group: 83 % of Respondents Indicated That “Performance Guarantees” Are A Prime Requirement for Voice Over Alternate Networks ¨ 50 % of Respondents Indicated That “Gateway Traffic Repots” Should be Capable of Providing the Necessary Call Detail Records and Other Specified Traffic Data John P. Yu November 13, 2006 Slide 45 of 48 Confidential *

References • • Voice Over IP; Uyless Black, Prentice Hall, 1999 Voice Over Data References • • Voice Over IP; Uyless Black, Prentice Hall, 1999 Voice Over Data Network; Gilbert Held, Mc. Graw-Hill, 1998 Compact PCI, Computer Telephony Specification, January, 1998 Spectral Compatibility of Digital Subscriber Line (DSL System Tutorial, August, 2000) • Transmission Systems for Communications, Bell Telephone Laboratories, Inc. , Fourth Edition, February 1970 • Communication Systems, B. P. Lathi, John Wiley & Sons, Inc. 1968 • Engineering and Operations in the Bell system, Bell Telephone Laboratories, Inc. 1978 John P. Yu November 13, 2006 Slide 46 of 48 Confidential *

References (Continued) • Solutions to Problems in Modulation Theory, by Harold S. Black, Van References (Continued) • Solutions to Problems in Modulation Theory, by Harold S. Black, Van Nostrand 1953 • How to choose the Right Dense Wavelength-Division Multiplexing (1525 to 1570 nm) • Interactive Video Display Systems, by John P. Yu 1982 • Worldwide Video Standards, Bell Telephone Laboratories, by John P. Yu 1980 • Technical Aspects of Data Communications, by John E. Mc. Namara, Digital Equipment Corporation 1978 • Bell system Technical Reference - Switched Network Transaction Telephone System, Pub 41804 John P. Yu November 13, 2006 Slide 47 of 48 Confidential *

References (Continued) ¨ Voice Over Whatever: Internet, IP, Frame Relay, and ATM Find Their References (Continued) ¨ Voice Over Whatever: Internet, IP, Frame Relay, and ATM Find Their Voice; Telecommunications Planning Service, The Yankee Group, December 1997 ¨ Vo. IP: The Opportunity Why You Should Become An ITSP, Internet Telephony, July, 1999 ¨ Internet Technology Focus; August, September & October 1999 ¨ Lucent Website - http: //www. lucent. com ¨ Cisco Website - http: // www. cisco. com ¨ Dialogic Website - http: //www. dialogic. com ¨ Brooktrout Website - http: //www. brooktrout. com ¨ Internet Telephony - Strategies, Solutions and Products; Andreas Wolf, ITK, AG, March, 1998 ¨ Voice Over IP Networks; Marcus Goncalves, Mc. Graw-Hill, 1999 ¨ Delivering Voice Over IP Networks; Daniel & Emma Minoli, John Wiley & Sons, 1998 John P. Yu November 13, 2006 Slide 48 of 48 Confidential *