We think you have liked this presentation. If you wish to download it, please recommend it to your friends in any social system. Share buttons are a little bit lower. Thank you!
Presentation is loading. Please wait.
Published byMalachi Jay
Modified about 1 year ago
© 1998 D. O’Mahony1 Internet Telephony Dr. Donal O’Mahony Networks & Telecommunications Research Group Trinity College Dublin
© 1998 D. O’Mahony2 Agenda Background to Internet Telephony Conventional Telephony –Network Structure, Key technologies, Delay, Echo Internet Telephony Technology –1st Generation Protocols, Compression Techniques Product Review
© 1998 D. O’Mahony3 Agenda….. 2nd Generation Systems –H.320 Standards –Product Review Directory Systems –IRC..LDAP Integration with the PSTN –Gateways, Next Generation Telcos Standards Organizations –VoIP Consortium, ETSI TIPHON
© 1998 D. O’Mahony4 Agenda... Case Studies Future Directions Implications for… –Large Corporations –Small Companies –Software Developers –Computer Network Managers –Network Operators –Telephony Equipment Vendors
© 1998 D. O’Mahony5 Origins of Internet Telephony Xerox PARC started the EtherPhone project between – used Ethernet as transport - concerned with Integration and advanced telephony
© 1998 D. O’Mahony6 VAT Lawrence Berkeley Laboratories developed the Video Audio Tool (VAT) in late 1992 –Work carried out by M-BONE team –Mainly interested in Conferencing/Collab oration CU-SeeMe from Cornell in early ‘94
© 1998 D. O’Mahony7 Major Technology Changes Phenomenal Internet Growth –1992: > 1 million hosts, ‘93: 2 million, ‘94: 3 million, ‘95: 5 mn, ‘96: 13 mn, ‘97: 19 mn, ‘98 30 mn SUN Audio …. PC Audio Cards become commodity items Processors becoming more powerful - Intel 386 can easily handle uncompressed audio Availability of cheap modems at 28 and 32 Kbps Massive Competition in Global Telephony Services - Callback etc.
© 1998 D. O’Mahony8 Dawn of Internet Telephony Vocaltec - an Israeli startup company launched their Internet Phone in February ‘95 By 1997, this had grown to more than 35 competing Phone products - Optimistic Forecasts Source: Frost & Sullivan
© 1998 D. O’Mahony9 Users Perceptions of Internet Telephony [Source Forester Research] 69% of Fortune 1000users plan to use Internet Telephony by 2000 or later Barriers to entry –Need proof of cost savings (48%) –Quality and Reliability(42%) –Awaiting endorsement by major players(25%) –Technology needs to mature(17%) Spending (and Saving) on Internet Telephony tolls will grow: (in billions) –1998:$0.03, 2000:$0.4, 2002:$1.03, 2004:$1.97
© 1998 D. O’Mahony10 Conventional Telephony Very large industry e.g. Telecommunications Service Revenue in 1994 was $195 billion, UK was $25 billion Historically made up of Monopoly Carriers operating in an uncompetitive environment
© 1998 D. O’Mahony11 Network Structure Analog Telephone Local Loop Telco Digital Switch Telco Digital Switch Digital Trunk ISDN Digital Phone International Gateway
© 1998 D. O’Mahony12 Digitizing Voice Telephone Network is engineered to carry a frequency range of 300 Hz to 3.4 KHz Achieved using 8,000 samples per second, 8 bits per sample –Yields standard 64Kbps Pulse Code Modulated (PCM) data stream
© 1998 D. O’Mahony13 Digital Trunk Circuits In Europe –E x64Kbps = 2Mbps –E2 - 4 x E1 + framing approx 8Mbps –E3 - 4 x E2 + framing approx 34Mbps –E4 - 4 x E3 + framing approx 140 Mbps Signaling Information is carried using a protocol called Common Channel Signaling System #7 or SS# S
© 1998 D. O’Mahony14 Originating Exchange Intermediate Exchange Initial Address Message Address Complete Ring Tone Answer Conversation Clear Forward Release Guard X X X X Speech Path established Speech Path Cleared Call Setup for a Typical Phone Call
© 1998 D. O’Mahony15 Voice Path Voice incurs some delay at each stage –e.g. 0.3ms for PCM coding, 5 s per km of optical fibre –Imperfections in Hybrid cause some echo –combination of delay and echo can cause problems CCITT G.114 recommend –one-way delays of 0-150ms are acceptable –150ms-400ms acceptable provided echo control/suppression is used >400ms is unacceptable 2-wire Analog Hybrid PCM Codec PCM Codec 2-wire Analog 2 independent digital streams
© 1998 D. O’Mahony16 Conventional Telephony Summary Provides a global network with very high connectivity Network Characteristics –circuit switched –constant bit-rate - 64Kbps –High Quality - 64Kps –Guaranteed Max Delay (<400msec) Service –Expensive –Lo-Tech [ IN-Services?] –Not Integrated
© 1998 D. O’Mahony17 Competition Traditional Monopolies are facing competition in all areas –Local Loop Regulators insisting on free access to multiple operators New Technologies: Wireless Local Loop, Cable Telephones, Electric Power Lines –National Network New infrastructure providers: Railway Companies, Electric Power Companies, Private Microwave Networks –International Networks Emergence of Mega-Carriers and Alliances –Call-Back….
© 1998 D. O’Mahony18 Telephone Tariffs National tariffs are set by PNO (often monopoly) International tariffs agreed on a bilateral basis –Accounting rate” mechanism invented in 1865 for telegraph traffic –Countries A and B agree that it costs $X dollars/min to terminate a call - any imbalance in the call-minutes between them leads to settlement payment of $X/2 per minute of the imbalance Calls can’t get cheaper than the settlement rate Inefficient (expensive) carriers are rewarded - U.S. paid out >$5billion in 1994 Large Call-Back market has developed –Internet Telephony circumvents the accounting rate
© 1998 D. O’Mahony19 Call-Back Accounted for Estimated 600 million minutes traffic in 1995 ~equiv 1% Total Telephone Traffic or 4% of outgoing U.S. Traffic Assuming a call-back average rate of US$0.45 => Call-back was US$270 million business in 1995 and growing
© 1998 D. O’Mahony20 Internet Telephony –Internet Network Structure –IP Datagram - a variable sized packet is delivered in store-and-forward fashion across a network of routers –Service is un-reliable, variable delays, variable bit rate, designed for data –Fixed Cost- usually cheap IP IP Datagram IP Router IP Router IP IP Datagram
© 1998 D. O’Mahony21 Using the Internet to carry Voice The 1st Generation Capture sound using SoundBlaster Card Code using 64Kbps - or other codec Pack into simple frames Send using User Datagram Protocol to fixed or pre-arranged port at pre-arranged address Timestamp used to detect lost frames - substitute comfort noise Sequence Number Flags Audio Format Speech Samples Timestamp
© 1998 D. O’Mahony22 Voice Coder/Decoder (CODEC) Simple PCM 64Kbps is covered by G finalized in 1972 G Kbps in 1988 ETSI GSM - Regular-Pulse Excitation - Linear Predictive Coding 13Kbps - in 1987 Seat of the pants…. Throw away every second sample More advanced algorithms were developed in later years
© 1998 D. O’Mahony23 Delay Sound captured in sound card - Delay dependent on buffer size Codec Delay e.g. RPE-LPC has 20ms delay TCP/IP stack - packet assembly delay V.34 modem introduces 35ms delay Delay in Internet Transit ?????? - unpredictable, depends on network load, destination e.g. 10ms to 500ms and more Jan’98 - UUNet ExtraLink VPN guarantees <150msec delay, Sprint’s VPN is <140msec
© 1998 D. O’Mahony24 Making the Connection The Internet allows packets to be sent to a specific IP address/port Phone software must be running and caller must know IP/port before a call can be setup Particularly difficult if IP address is dynamically assigned - dialup internet access is a problem Need some kind of address server IP Address/Port Address Server Caller Callee
© 1998 D. O’Mahony25 1st Generation Internet Phones Vocaltec IPPhone –announced February 1995 –Offered a range of Codecs Vocaltec VSC 8Khz The DSP Group’s TrueSpeech 8Kbps GSM –Used Internet Relay Chat (IRC) Server Network to find callees IP address Cost: Initially $100 down to $50
© 1998 D. O’Mahony26 1st Generation Internet Phones WebPhone from Netspeak Corporation (aka Internet Telephony Company) Launched ver 1.0 in August ‘95 Had many additional features –voice mail, four line display, caller ID, Do not disturb, Speed Dial, Call Hold/Mute, Conversation Encryption –Uses Enhanced GSM (12Kbps) or TrueSpeech(8.5Kbps) Address Server can only be searched - not browsed
© 1998 D. O’Mahony27 1st Generation Internet Phones Netscape Cooltalk –Released with Netscape 3.0 in March 1996 –Cross-Platform availability : W3.1,W95,WNT,Power Mac, Solaris, HPUX, Iris, DEC UNIX –Uses GSM and Voxware RT-24 (2.4Kbps) –Incorporates Echo Cancellation and Silence Surpression Controls –Also includes a chat tool and shared whiteboard –Used IS411 Server to establish contact with other users
© 1998 D. O’Mahony28 1st Generation Internet Phones SpeakFreely First public release in August ‘95 - developed by John Walker (founder of AutoDesk) Large variety of protocols : SF, RTP, VAT Large variety of codecs: PCM, GSM, LPC, LPC- 10 Security features - can use PGP for key agreement Look-Whos-Listening Server for contact
© 1998 D. O’Mahony29 1st to 2nd Generation First generation systems all took different approaches to –connection setup, negotiation –protocol encapsulation –add-ons e.g. white-board, chat tools –No interworking was possible
© 1998 D. O’Mahony30 H.320 Series Recommendations Originally developed to allow for Video- Telephony and Video-Conferencing applications across ISDN Networks H.320 was a framework for many other standards
© 1998 D. O’Mahony31 H.320 in Data Networks H.321 adapted the H.320 series to run on B-ISDN (ATM) network H.323 (May’96) did the same for networks with a non-guaranteed quality of service e.g. –Ethernet, Token Ring, FDDI or –IP –Should be possible to inter-work with H.320 terminals in ISDN or B-ISDN environments
© 1998 D. O’Mahony32 Call Signaling in H.223 A number of distinct phases are defined –Phase A - Call Setup - Can employ the services of a Gatekeeper –Phase B - Capability exchange –Phase C - Establishment of Audio-Visual Comms –Phase D - Call Services e.g. conference expansion –Phase E - Call Termination
© 1998 D. O’Mahony33 H.323 Protocol Stacks Physical Layer Link Layer Network Layer (IP) Unreliable Transport (UDP) Reliable Transport (TCP) T.123 (ISO+TCP) T.124 GCC T.125 MCS Real-Time Protocol (RTP) RTCP G.7XX Audio H.26X Video RAS Term. GW H Call Signal H.245 Call Signal AV Appl.Q.931 Terminal Control and Mgmt Data Appl. or T.126/T.127
© 1998 D. O’Mahony34 Channels A number of Logical Channels are setup for different purposes Audio/Video are encapsulated in the Real Time Protocol (RTP) - specs for H.261, G.7111 etc Control/Signaling Channels use TCP A Resource Reservation Protocol (RSVP) channel is setup to allow resources to be reserved (if supported) and for feedback on QoS to be exchanged T.120 provides for data applications such as chat & whiteboard
© 1998 D. O’Mahony35 ITU Codecs All codecs are available for licencing Source: Lucent
© 1998 D. O’Mahony36 2nd Generation Internet Phone Microsoft Netmeeting Netmeeting 2.1 supports H.323 for video/audio conferencing, application sharing,shared clipboard, file transfer, whiteboard Many different codecs supported for audio including G.723.1, Lernout & Haspie (5-16Kbps) Uses ILS to locate users
© 1998 D. O’Mahony37 2nd Generation Internet Phone Intel IVPhone
© 1998 D. O’Mahony38 2nd Generation Internet Phone Netscape Conference 4.0 Released as an integral component of Netscape Communicator –Supports H.323 audio conference only, whiteboard, chat, collaborative web browsing and file transfer –Range of codecs: G.711, telemedia SX 8300P, Voxware RT-29/RT-24 –Uses a Dynamic Lookup Server at four11.com to locate called parties
© 1998 D. O’Mahony39 2nd Generation Internet Phone Vocaltec Internet Phone 5.0 Supports H.323, with Video, but not by default - chat, whiteboard file transfer possible 5 codecs supported - Vocaltec VSC is default - proprietary video codec too Uses Community Browser with interest groups to find callee Good support for PC calling via Delta3 and others
© 1998 D. O’Mahony40 Future H.323 Changes ITU ratified H.323 Ver 2 in Jan/Feb‘98 Major updates: Refinements for Internet [Telephony] Addressing, Directory, Scalability, QOS Encryption Large scale conferences Distance learning, Auditorium mode Richer media control layered video codecs, reopen of LCs, ‘big pipes F Feature creep more Facility signaling, redundancy, FastStart IETF alignment
© 1998 D. O’Mahony41 H.323v2 enhancements H.235 – Enhanced Security Allows users to authenticate themselves using passwords, certificates or challenge- response mechanisms –Will allow Internet Telephony users to authenticate themselves to Gateways and/or Gatekeepers Fast Call Setup –possible to setup a call using a single Round Trip
© 1998 D. O’Mahony42 Vocaltec Gatekeeper Announced Feb’98 - availability Q2’98 - runs on NT Server 4.0 Targeted at ‘carrier-grade’ IP Telephony for service provider and corporate markets Provides centralized addressing for IP terminals Can provide least cost routing (e.g. via PSTN G/W or Internet) Performs Authorization & Billing using H.235 security SNMP Manageable or using Vocaltec Network Manager
© 1998 D. O’Mahony43 Directory Services Need a Phonebook equivalent Present systems often list all available users Some attempt to categorize into communities (e.g. General, Music, with camera etc) Invites calls from strangers! Novelty factor will decline
© 1998 D. O’Mahony44 Internet Relay Chat (IRC) Already existing network of servers to allow text- based chat rooms Initially Vocaltec used the Join and list primitives of IRC as a rendezvous mechanism Dedicated Network of Internet Phone servers grew up Latest release uses a Community Browser - which uses a development of this mechanism
© 1998 D. O’Mahony45 Bigfoot,Switchboard, Infospace, Four11 Internet Telephony can use any mapping of E- mail->IP Address Many on-line directory services that register users can store this information on request Access via general purpose or specialized WWW browsing software
© 1998 D. O’Mahony46 User Location Service ULS is a Dynamic Registration Protocol designed by R. Williams in now an expired internet draft Four11 (www.four11.com) operates a directory service based on a User Location Service (ULS) protocol –supports Connectix VideoPhone,CU-SeeMe,Netscape CoolTalk,VDOnet's VDOPhone,Netspeak WebPhone Microsoft NetMeeting –Identifies user who has come on-line, with internet address and phone application
© 1998 D. O’Mahony47 LDAP A Lightweight version of the X.500 Global Directory Access Protocol- now at 2.0 Designed for static information - no facility for refresh and expire operations LDAP 3.0 will support this X.500 Directory Hierarchy of Objects Read, search, modify
© 1998 D. O’Mahony48 LDAP 3.0 Many facets to the 3.0 extensions - but dynamic entries are of principal interest to Internet Telephony - Internet Draft at Dec’97 ftp://ietf.org/internet-drafts/draft-ietf-asid- ldapv3-dynamic-07.txt - now submitted as a proposed standard dynamicObject Class EntryTTL attribute (secs) Refresh(NewTTL)
© 1998 D. O’Mahony49 Microsoft Internet Locator Service Based on LDAP 2.0 with proprietary extensions Defines a User Object and a Meetingplace Object No Compatible Servers : Example ls5.microsoft.com Will migrate to LDAP 3.0 in the future Country CName Description Atendee user Meeting Place Registration,Unreg, Refresh, Resolve Query, Modify
© 1998 D. O’Mahony50 PSTN Integration Started with the ‘Free World Dialup’ experiment in October’95 Since local calls are free in many areas, the fledgling Internet Telephony community tried to establish primitive break-out’s into the PSTN Established gateways in Jakarta, Tokyo 7 New York - FWDII is underway Modified Modem I/Tel Software Internet
© 1998 D. O’Mahony51 Internet Telephony Gateways Generally consist of one or more PSTN lines and DSP support for Voice compression algorithms Example Dialogic Single-Line system approx $1,000
© 1998 D. O’Mahony52 Bulk Gateways Lucent technologies have developed ‘Internet Telephony Server-SP (Service Provider) to allow Phone-to-Phone calling across an internet link for many lines Netspeak Webphone Gateway Exchange (WGX) has up to 4 E1 or T1 interfaces (96 lines) –can interface to ACD hardware for VoIP Call Centre applications –working with Telestra on SS7 support for gateway
© 1998 D. O’Mahony53 Internet Telephony eXchange Carrier (ITXC) Subsidiary of AT&T - headed by Tom Evslin) former VP who ran AT&T Worldnet -started July’97- Vocaltec has minority stake provides wholesale switching, transport, billing and settlement functions to ITSPs (Internet Telephony Service Providers) for IP telephony (Internet telephony). ITSP Gateway Public Network ITXC Intranet
© 1998 D. O’Mahony54 Next Generation Telcos Delta Three !Operates an Internet Telephony Backbone providing !PC-to-Phone calling - use Vocaltec’s Internet Phone or (free) Delta3 Internet Phone Lite !Phone-to-Phone Calling (using calling card+pin) !Gateways around the world: London, HongKong, Paraguay, France etc !Economics !Codec Delta Three uses is 11 kbs !TCP/IP overhead adds 5 kbs !Kilobit range comes down by 40% with silence suppression !End result: typically under 10 kbs !Over 200 simultaneous calls over a data E1 !PC-to-Phone Tariffs e.g. Feb’98: US: 12¢/min, UK 16¢, Tokyo 19.5¢
© 1998 D. O’Mahony55 Other Next Generation Telcos US Global Link to offer Phone-to-Phone Internet Telephony –Plans to install 1000 internet telephony switces (175 by Jan’98) –rates of 20-40% lower than callback IDT and Net2Phone offering PC-to-Phone calls via their U.S. gateway VIP Calling offers Internet Telephony for carriers via their global network of pops
© 1998 D. O’Mahony56 Standards Organizations The Internet Telephony Interoperability Consortium Home A research organization focused on –interoperability, pricing, regulatory issues and business effects –act as a feeder body to standards orgs such as IETF
© 1998 D. O’Mahony57 The Internet Telephony Consortium 3 principal areas –Architecture for Interoperability control arch, call mgt and edge signalling, ULS/Mobility, Policy routing, standards –Efficient Resource Allocation network resource characterization, Economic Models, Performance models, Yield Mgt, user Feedback –Industry Structures, Business Strategies and Policy Business Model Framework, Business Strategies, Evolution and Convergence, Regulation and Policy Analysis, Strategies
© 1998 D. O’Mahony58 The Internet Telephony Consortium Planned Deliverables Applications Testbed: Construction of Experimental Setup and Conduct of Experiments Architectural Implications of Internet Pricing Models European Internet Regulatory Strategies Internet Telephony Business Models Internet Telephony Cost Model (Proposed - Internet Telephony Network Testbed) Internet Telephony Regulation and Policy Analyses Internet Telephony Strategies Interoperability of Directory Services Interoperability Requirements for Personal Mobile Multimedia Services Intranet Telephony Cost Model Meta-Net Architecture Roadmap of Standards for Internet Telephony Interoperability Taxonomy of Internet Telephony's Industrial Structure User Feedback Studies Yield Management
© 1998 D. O’Mahony59 Standards Organizations The Voice over IP Forum Interest Group of the IMTC (International Multimedia TeleconferencingConsortium ) - formed in May’96 –representatives mainly of multimedia software developers - focussed on interoperability –coordinate with H.323 interop group at IMTC March’97 - select G.723.1(6Kbps) as default codec Sponsor regular H.323 interoperability tests
© 1998 D. O’Mahony60 Standards Organizations ETSI Initial workshop help at Sophia Antipolis in March ‘97 1st formal meeting of the Telecommunications and Internet Protocol Harmonization over Networks (TIPHON) in late May’97 Focus is on Interworking between existing networks: PSTN, ISDN, GSM and VoIP
© 1998 D. O’Mahony61 TIPHON Project Status 3 Phases –Phase 1 - VoIP TO PSTN/ISDN/GSM - by end of ‘97 –Phase 2 - PSTN/ISDN/GSM TO VoIP - by end of June’98 –Phase 3 - PSTN.. To PSTN… via VoIP - by end of Sept’98 –Phase 4 - VoIP to VoIP via PSTN - by end Sept’98 –Project completion by end of ‘98 6 Working Groups: –WG 1 - Requirements for service interoperability –WG 2 - Architecture and reference configurations –WG 3 - Call control procedures –WG 4 - Naming, Numbering and Addressing –WG 5 - End-to-End Quality of Service aspects –WG 6 - Verification and Demonstration Implementation Feb’98 –Stable drafts for Phase 1 - table of contents for Phase 2
© 1998 D. O’Mahony62 Demonstration Network - TIPHONET –should demonstrate connectivity between nodes at ETSI (SophiaAntipolis), France Telecom (Caen) Post & Telecom Austria (Vienna and Graz) - Operational by mid-Nov’97
© 1998 D. O’Mahony63 Internet Engineering Task Force (IETF) Multiparty, Multimedia Session Control (MMUSIC) MMUSIC has drafted protocols for: –distributing session descriptions -- Session Description Protocol (SDP) and Session Announcement Protocol (SAP) –providing security for session announcements -- SAP Security –controlling on-demand delivery of real-time data -- Real-Time Stream Protocol (RTSP) –initiating sessions and inviting users -- Session Initiation Protocol (SIP) –managing tightly-controlled sessions -- Simple Conference Control Protocol (SCCP) SIP seen as an alternative for Internet Telephony –addresses directory services –much more light-weight and flexible than H.323 –Can gateway to Q.931, H.320 –main advocate: Henning Schulzrinne –http://www.cs.columbia.edu/~hgs/sip/ Also the PSTN IP Integration Group (PINT) addressing how IP apps can enrich and request PSTN services e.g. WWW yellow pds with dialling
© 1998 D. O’Mahony64 ACTA Petition On March 4th, 1996, the American Carriers Telecommunications Association petitioned the FCC to the effect: –Vocaltec, other s/w companies and ITSP are providing telephony services, and should be regulated –Not in the public interest to give away telephony services –FCC should stop ITSPs until new rules can be made –FCC has authority to regulate internet and ITSPs (as interstate carriers)
© 1998 D. O’Mahony65 VON Coalition On March 18th, the VON Coalition was formed to oppose ACTA petition –Over 400 individual and 80 corporate members –counter argument based on the fact that Internet Telephony is an emerging technology –No way to draw the line between IT and any networked multimedia application –IT can be used to link schools, libraries at low cost!
© 1998 D. O’Mahony66 Regulation Former FCC Chairman Reed Hundt in July ‘96 - We shouldn't try to impose old rules on new ideas.I'm against subjecting Internet telephony to the old rules that apply to conventional circuit-switched voice carriers, even while we're trying to change those rules. On Sept 8th ‘97: Statement by Larry Irving, National TeleC & Info Admin at VON Conference “President Clinton…spoken about need to let new telecom technologies blossom” New worries in February ‘98
© 1998 D. O’Mahony67 European Position Voice regulation is governed by EU Directive 90/388/EC On on 10th Jan’98, Commission issued a notice ( ) on Internet Telephony – following a period of public consultation Main Points –Technology will eventually cause a convergence of Internet and conventional Telephony –Today’s Internet Telephony cannot yet be characterized as a Public Telephone Service –No Universal Service Obligations Review in future at least by Jan 2000
© 1998 D. O’Mahony68 Internet Telephony Applications 2nd Line for Internet Users Telestra and Netspeak have developed SS#7 gateway to allow calls to active internet users Ericsson “Phone Doubler” - demonstrated in March’97 achieves similar results PSTN Internet Gateway
© 1998 D. O’Mahony69 Internet Telephony Applications Telecom Finland’s NeoPhone Service Integrated Voice/Data in one terminal Not an internet phone - voice carried across IP on corporate networks and across PSTN or between corporate networks using Telecom Finland’s ATM networks Integrated with TF’s Intelligent Network and VIPGate nation-wide company number service (VPN)
© 1998 D. O’Mahony70 Internet Telephony Applications Etherphone LAN PBX Phonet ( Israeli startup) produce EtherPhone which provides PBX functions over a LAN Etherphone servers can do limited ACD Can link Etherphones across WAN links LAN EtherPhone Server PSTN
© 1998 D. O’Mahony71 Internet Telephony Applications VocalTec’s Surf&Call Plug-in for Netscape 3.0 or Internet Explorer 3.0 Allows “CALL” buttons to be put on WWW pages Pressing initiates an Internet Telephony Call to call centre
© 1998 D. O’Mahony72 Future Developments Convergence on Codec’s (G [6.3Kbps] or G.720 Annexe A [8Kbps]) –Efficient implementations Low Delay TCP/IP stacks Increased support for RTP Incorporation of Java Media Framework API Adoption of LDAP shakeout in directory services area
© 1998 D. O’Mahony73 Future Developments... Increased support for H.323 additional function e.g. call transfer, call waiting, ACD features Convergence of PBX and IP Telephony Server More support for H.320 multipoint operation Each availability of MCUs Much more users
© 1998 D. O’Mahony74 Implications of Internet Telephony for Large & Small Companies Opportunity to integrate voice/data PBX replacement New opportunities to route calls to achieve cost savings - over corporate intranet, via next gen telcos Better service to customers using Call Centres coupled with Internet Telephony
© 1998 D. O’Mahony75 Implications of Internet Telephony for Software Developers Represents a paradigm shift in telephony Opportunites to provide components of the overall solution Gateways, Management, accounting, end-to-end security, routing, firewalls etc. New lease of life for ISDN-based (H.320) systems
© 1998 D. O’Mahony76 Implications of Internet Telephony for Computer Network Managers Play increasing role in Telephony service provision Challenge of ensuring Network QoS Increased reliability constraints Need Multi-media and networking competence in Support function
© 1998 D. O’Mahony77 Implications of Internet Telephony for PTOs As Internet Telephony grows : - gain in local call revenues, leased lines, loss in International Calls Many US telco’s have no local call charges - =>loss Tarifica’s NetEffect Study
© 1998 D. O’Mahony78 Impact on PTOs.. Some new opportunities Extra Leased line revenue Opportunities for backbone service provision Adopt two-tier pricing : circuit-switched and packet-switched –maintain price-sensitive customers –lower network cost –bypass accounting rate system Jan’98 Conference: How an ISP can become a TELCO!
© 1998 D. O’Mahony79 Implications of Internet Telephony for Telephony Equipment Vendors Paradigm Shift Telephony no longer a separate market Increasing competition from Computer community PBX will become a network server/gateway Decreased demand for concentional phone Emergence of PCs disguised as phones!
© 1998 D. O’Mahony80 Conclusions A time of great change –from Ham-Radio to fledgling industry in 2-3 years Will affect many different industries Creates many different threats and opportunities Clear that Internet Telephony is here to stay
UNIT I FUNDAMENTAL OF E-COMMERCE 1.1INTRODUCTION TO E-COMMERCE 1.2 DRIVING FORCES OF E-COMMERCE 1.3 BENEFITS AND LIMITATIONS OF E-COMMERCE 1.4 DATA MINING.
TCOM 590: Comprehensive Voice over IP George Mason University Dragan Hrnjez Spring 2014.
Ch 5 : Multimedia Network Standardization, QoS, Access Media Science and Technology Faculty Informatics Arini, ST, MT Com
Introduction to Telecommunication Equipment: PBX, ACD, IVR, CMS, CAS and Workforce Management or How to Select Telephone Systems & Services to Fit Your.
ITU-TSG16 ITU-T Standardization Seminar – Madrid, December 2002 H.323 and some Security-related issues – a presentation in two parts Simão Ferraz.
Network+ Guide to Networks 5 th Edition Chapter 11 Voice and Video Over IP.
Copyright 2011John Wiley & Sons, Inc Data Communications and Networking 11th Edition Jerry Fitzgerald and Alan Dennis John Wiley & Sons, Inc Dwayne.
CHTP REVIEW. HFTP Todays Session Structure Four-Hour Review Designed for Exam Review Sectioned Same as Exam Breaks when needed.
Introduction to Telecommunication Equipment 101 or How to Select Telephone Systems & Services to Fit Your Needs Bill Brackin Program Director, North Sound.
1 © 2007 Avaya Inc. All rights reserved. Understanding SIPs Role in Intelligent Communications Tom Doria Director – Avaya P2P Technical Business Development.
Carleton University 1 February 25th, 2014 Voice over IP Presenter: Tony Hutchinson System Engineering Manager.
Internet Application Development What is the Internet anyway? Colm O Suilleabhain.
Networking Fundamentals John Bellavance CCNI. Data Networks Developed because companies wanted to exchange info over long distances. At first they used.
1 Computer Networks: A Systems Approach, 5e Larry L. Peterson and Bruce S. Davie Chapter 9 Applications Copyright © 2010, Elsevier Inc. All rights Reserved.
Mass media refers collectively to all media technologies that are intended to reach a large audience via mass communication. Broadcast media (also known.
The Whirlwind Tour Chapter 1a. 2 Transactions: Where It All Started [Cuneiform] documents now number about half a million, three- quarters of them more.
7.1 © 2007 by Prentice Hall 7 Chapter Telecommunications, the Internet, and Wireless Technology.
What is an Operating System? A program that acts as an intermediary between a user of a computer and the computer hardware. Operating system goals: Execute.
Information Systems Using Information (Higher and Intermediate 2)
MSc WLAN, IP/TCP and COMM NETWORK Topics By Prof R A Carrasco School of Electrical,Electronic and Computer Engineering University of Newcastle Upon Tyne.
Network+ Guide to Networks 6 th Edition Chapter 12 Voice and Video Over IP.
Wireless Communications UniForum Chicago October 26,2004 Bill Latura.
COMPUTER NETWORKS. COMMUNICATION BETWEEN COMPUTERS For a computer to communicate with each other (which may be a completely different system) an interface.
APNOMS02, Jeju, Korea1 QoS Control in the Internet Raouf Boutaba QoS Control in the Internet Raouf Boutaba School of Computer Science University of Waterloo.
Copyright © 2007 Pearson Education, Inc. Slide 3-1 E-commerce Kenneth C. Laudon Carol Guercio Traver business. technology. society. Third Edition.
Call Recording Made Easy Presented by Barbara Courneya National Director of Contact Center Technology Avaya Certified Contact Center Expert ,
Version 4.1 CCNA Discovery 2– Chapter 7. Contents 7.1: ISP Services : TCP / IP Protocols 7.2: 7.3: DNS 7.3: 7.4: Application Layer Protocols 7.4.
© 2016 SlidePlayer.com Inc. All rights reserved.