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  1. 1. Voice over IP Information Systems 311 November 19, 2002
  2. 2. How do computers communicate <ul><li>1968 ARPA created a standard by which these computers could communicate known as TCP/IP. </li></ul><ul><li>TCP/IP specifies the details of how computers communicate as well as a set of conventions for interconnecting networks and routing traffic. </li></ul><ul><li>TCP/IP is the standard by which computer communicate whether its an internal client/server (little “internet”) or one connects through other networks that spans geographic distance (big “Internet”) </li></ul><ul><li>Therefore TCP/IP is the base technology for the Global Internet that connects over 170 million individuals in virtually all populated countries around the world. </li></ul>
  3. 3. Some Differences <ul><li>TCP - transmission control protocol </li></ul><ul><li>Connection orientated circuit (established connection between two hosts and exchanges streams of data) </li></ul><ul><li>Considered a reliable protocol because it guarantees delivery of data and the order of the packets that its sending. </li></ul><ul><li>Down-side – requires constant bandwidth to maintain the connection </li></ul><ul><li>TCP/IP layers where split in the seventies to handle larger volumes of information </li></ul>
  4. 4. More <ul><li>IP – Internet Protocol </li></ul><ul><li>Connection-less orientated circuit </li></ul><ul><li>IP works on the packet level </li></ul><ul><li>Specifies the format of the packets and the addressing scheme </li></ul><ul><li>Consider unreliable – individual packets send by by effort routing and can arrive out of order. </li></ul><ul><li>Packets are switched doesn’t require constant bandwidth </li></ul><ul><li>Benefit IP packets can encapsulated with several types of information like Voice </li></ul>
  5. 5. TCP/IP work within the Internet Model <ul><li>The Internet’s 5-Layer Model (top – down hierarchy) </li></ul><ul><li>  </li></ul><ul><li>Application : used by application program - the start of the five - layer process. </li></ul><ul><li>Transport : establishing end-to-end connections, translates domain names into numeric addresses, and segments messages (also known as the TCP layer) </li></ul><ul><li>Network: responsible for end-to-end addressing and routing, determines destination address if unknown (also known as IP layer) </li></ul><ul><li>Data Link : deals with message delineation, error control & network access </li></ul><ul><li>  Physical : defines how information will be transmitted through the network </li></ul>continued...
  6. 6. VoIP – Definitions <ul><li>What is it? </li></ul><ul><li>How does it work? </li></ul><ul><li>Standards involved </li></ul>
  7. 7. VoIP – What is it? <ul><li>Voice over Internet Protocol </li></ul><ul><li>Introduction of VoIP in 1995 by Vocaltec Inc. </li></ul>
  8. 8. VoIP – How does it work? <ul><li>Converting the voice signal </li></ul><ul><ul><li>ADC (analog to digital) </li></ul></ul><ul><ul><li>DAC (digital to analog) </li></ul></ul><ul><li>Voice (source) - - ADC - - - Internet - - - DAC - - Voice (dest) </li></ul><ul><li>Transmission of voice traffic in packets </li></ul>
  9. 9. VoIP – Standards Involved <ul><li>H.323 V.2 – Most widely supported </li></ul><ul><ul><li>used for packet based multimedia communication systems </li></ul></ul><ul><li>Media Gateway Control Protocol (MGCP) </li></ul><ul><li>Session Initiation Protocol (SIP) </li></ul>
  10. 10. VoIP – Applications <ul><li>VoIP could be applied to almost any voice communications requirement, ranging from a simple inter-office intercom to complex multi-point teleconferencing/shared screen environments. </li></ul><ul><li>For example… </li></ul>continued...
  11. 11. VoIP – Applications <ul><li>A network configuration of an organization with many branch offices (e.g., a bank) that wants to reduce costs and combine traffic to provide voice and data access to the main office. </li></ul>continued...
  12. 12. VoIP – Applications <ul><li>In this VoIP application, an organization wishes to send voice traffic between two inter-office locations over the packet network and replace the PBXs connections at these locations. </li></ul>continued...
  13. 13. VoIP – Applications <ul><li>A third application of VoIP software is inter-working with cellular networks . </li></ul>
  14. 14. VoIP – Applications <ul><li>Other applications: </li></ul><ul><ul><li>e-commerce – multi-service applications (call button) </li></ul></ul><ul><ul><li>conferencing systems that may include shared screens, whiteboarding, etc </li></ul></ul>
  15. 15. Marketing application for Venetian
  16. 16. VoIP – Pro and Cons <ul><li>Benefits of the VoIP technology can be divided into the following four categories: </li></ul><ul><li>Cost Reduction </li></ul><ul><li>Simplification - an integrated infrastructure </li></ul><ul><li>Bandwidth Consolidation </li></ul><ul><li>Advanced Applications </li></ul>
  17. 17. VoIP – Pro and Cons
  18. 18. VoIP – Pro and Cons <ul><li>Quality-of-service (QoS) issues </li></ul><ul><li>Delay problems: echo, talker overlap and jitter </li></ul><ul><li>Too many standards </li></ul>
  19. 19. VoIP – Pro and Cons
  20. 20. VoIP – Security Issues <ul><li>Transmissions </li></ul><ul><li>Unauthorized use </li></ul>
  21. 21. Solution for transmission issue <ul><li>Check Point Software </li></ul><ul><li>Aravox </li></ul><ul><li>Nortel Networks </li></ul><ul><li>Aspect Communication </li></ul>
  22. 22. Security - Check Point Software <ul><li>Stateful Inspection of Web services traffic from the network layer to the application layer </li></ul><ul><li>Centralized management with SmartCenter </li></ul><ul><li>Authentication, authorization and secure sign-on with UserAuthority(TM) </li></ul><ul><li>Prioritization of Web services traffic using Check Point's Quality of Service (QoS) solution, FloodGate-1 </li></ul>
  23. 23. Security - Aravox <ul><li>Provides a limitless platform for voice service providers. </li></ul><ul><li>E.g. IP Centrex unified messaging, instant conferencing, presence and instant messaging </li></ul><ul><li>Aravox was the first company creating a carrier-class real-time IP services gateway enabling backbone carriers, access providers and enterprises to deploy secure, real-time communications on converged networks </li></ul>
  24. 24. Solutions for unauthorized use <ul><li>Use a personal identification number </li></ul><ul><li>Restrict employees dialing access </li></ul><ul><li>Track phone calls </li></ul><ul><li>Employee monitoring </li></ul><ul><li>Gateways eliminate crank calls and telemarketers </li></ul>
  25. 25. Other Solution <ul><li>VPN </li></ul><ul><li>VPN hardware and software installation </li></ul><ul><li>Use this over WAN </li></ul><ul><li>Offers high strength encryption keys </li></ul><ul><li>Protect both data and the networks </li></ul>
  26. 26. The Telephone Network <ul><li>Originally designed for analog communications only. </li></ul><ul><li>Today, standard analog telephone service is called POTS (Plain Old Telephone Service). </li></ul><ul><li>Modem communications use the telephone network to send digital data. </li></ul><ul><li>Modems use carrier waves to send information </li></ul>
  27. 27. Traditional Long Distance <ul><li>Pick up phone </li></ul><ul><li>Dial </li></ul><ul><li>Long distance provider </li></ul><ul><li>Pay connection fee and per minute charge </li></ul><ul><li>Billed monthly </li></ul>
  28. 28. VoIP Long Distance <ul><li>Pick up phone </li></ul><ul><li>Dial number </li></ul><ul><li>VoIP provider </li></ul><ul><li>Internet </li></ul><ul><li>Receiver’s VoIP provider </li></ul><ul><li>This eliminate large phone bill </li></ul>
  29. 29. VoIP - Demonstration <ul><li>Yahoo Messenger </li></ul><ul><li>I will use the Voice Over IP feature of the messenger to Chat </li></ul><ul><li>This works world wide for free (except ISP fee) </li></ul><ul><li>For this Demonstration will be to Minnesota - approx. 1500 miles away. </li></ul>
  30. 30. VoIP - Expected growth and future <ul><li>By 2007 VoIP will account for approx. 75% of the worlds voice services. </li></ul><ul><li>Many companies are using VoIP on their managed private networks to save money </li></ul><ul><li>Extremely likely the PBX’s will offer IP as and added value service – like IP/PBX phone system </li></ul><ul><li>Has fantastic potential for e-commerce applications </li></ul>
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