The Future of Voice over Internet Protocol

1
The Future of Voice over Internet Protocol

• Presenter Scott Martin
• April 12, 2007

2
Introduction

• What is Voice Over Internet Protocol (VoIP)?
• The two-way transmission of audio over a
  packet-switched IP network.
• When used in a private intranet or WAN, it is
  generally known as 'voice over IP,' or 'VoIP.'
• When the transport is the public Internet or the
  Internet backbone from a major carrier, it is
  generally called 'Internet telephony.

3
Introduction

• Voice Over Internet Protocol (VoIP)
• History
• Implementation
• Service Types
• Benefits
• Drawbacks
• Current and Projected Use

4
History of VoIP

• Network Voice Protocol
• Created in 1973 by Danny Cohen at USC
• Project Goals
• Wanted to create digital high-quality,
  low-bandwidth, secure voice handling capability
• Control Protocol
• Data Transport Protocol

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Circuit Switching

• Current Phone Systems
• Dedicated line with a constant connection
• Originally very expensive
• Each call transmits at 64 kilobits per second
• 64 kbps x 2 directions 128 kbps
• 128 kbps 16 kilobytes per second
• During a 10 minute call, about 10 MB
• Highly inefficient

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Circuit Switching

• Example Circuit Switching

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Packet Switching

• VoIP Phone Systems
• Connection only long enough to send a packet of
  information
• Thousands of possible paths for packet to go
• Network uses cheapest and least congested paths
• Quality of Service (QoS)
• A 10 minute call transfers only about 2 MB

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Packet Switching

• Example Packet Switching

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Quality of Service (QoS)

• Defined in the International Telecommunication
  Union standard X.902
• A set of quality requirements on the collective
  behavior of one or more objects.
• Control mechanisms to provide different
  priorities to different users or data flows
• Important for real-time streaming applications

10
VoIP Implementation

• Sender picks up the phone
• Analog telephone adapter (ATA)
• Data converted by a codec
• Soft Switch
• Receiver picks up ringing phone
• Data transfer during calls is handled by current
  internet infrastructure

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Analog Telephone Adapter (ATA)

• Converts audio between analog and digital signals
• Need one on each end of the call
• Sends signal to handle connect and disconnect

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Codecs

• Coder-decoder or codecs
• Conversion from analog audio signal to digital
  signal
• Most common codec is the G.729A
• sampling rate of 8,000 times per second
• Conjugate-structure Algebraic-code-excited Linear
  Prediction algorithm (CS-ACELP)
• Responsible for the large gap in performance

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Soft Switches

• Database mapping program
• Endpoint-to-Endpoint
• Location
• Phone Number
• IP address
• Allows phones, computers, and WiFi phones to work
  together

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Industry Protocol Standards

• H.323 Protocol Suite
• Main flaw not designed for VoIP

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Industry Protocol Standards

• Session Initiation Protocol (SIP)
• Smaller, more efficient
• Designed specifically for VoIP
• Handles
• User location
• User capabilities
• User availability
• Call setup
• Call handling

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VoIP Service Types

• Home Phones
• Requires an ATA
• Usually provided for free
• IP Phones
• ATA technology built in
• Ethernet Phones
• WiFi Phones
• Computer-to-Computer calls

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Computer-to-Computer VoIP

• Simplest and cheapest way to use VoIP
• Requires
• Microphone
• Speaker
• Sound card
• Broadband internet
• Costs Software and ISP service
• Calls Free
• Example Skype Download Service

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Benefits

• Uses technology already in common use
• Cost
• Bundled Services
• Caller ID
• Voice Mail
• Call Waiting
• Call Forwarding
• Many Others
• Long Distance and International Rates

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Benefits
Cost of Calls Made from US to Foreign Countries
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Drawbacks

• 911 Emergency Calls
• Dependence on Wall Power
• Latency issues, jitter, and packet loss
• Viruses, worms, and hackers
• Integration with land-line dependant hardware
• DVRs, digital television service, and home
  security systems

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Drawbacks

• Security
• Problems sending faxes
• Dependence on Internet Service Providers
• Requirement of broadband connectivity
• WiFi hotspot dependence

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Current and Projected Use

• Roughly 6 million in US in 2006
• Expected to climb to 24 million by the end of
  2008
• Increase in service providers
• Traditional phone companies
• AtT, Sprint, Nextel, Time Warner
• VoIP companies
• Skype, Vonage, VoIP Inc.

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Conclusion

• VoIP will be a dominate force in the 21st century
• Probably at least another 10 years before
  possibly replacing current phone systems
• If the current flaws are fixed sooner rather than
  later, it could be much sooner than a decade

24
References

• Wikipedia. Network Voice Protocol. March 2007
  (http//en.wikipedia.org/wiki/Network_Voice_Protoc
  ol)
• Valdes, Robert. HowStufWorks. How VoIP Works.
  May 2001 (http//electronics.howstuffworks.com/ip-
  telephony.htm)
• Protocols.com. Voice Over IP Protocols. March
  2007 (http//www.protocols.com/pbook/VoIP.htm)
• Bell, Michael. Ways to Use VoIP. 2007
  (http//ezinearticles.com/?Ways-to-Use-VoIP-Techno
  logyid125070)
• VoIP.com. 2007 (http//www.voip.com/)
• ATT.com. ATT International Rate Finder. 2006
  (http//www.consumer.att.com/global/english/intern
  ational.html)
• BellSouth.com. International Calling Plan
  Rates. (http//www.bellsouth.com/consumer/bsld/ic
  pRates.html)
• Qwest. Qwest OneFlex International Rates. 2007
  (https//cvoip.qwest.com/oneflex/portal/residentia
  l/products/voip/ratesl)
• Verizon. Country Code and International Rate
  Finder. 2007 (http//www22.verizon.com/ForYourHom
  e/LD/WorldCaller.asp)10 FCC Consumer
  Governmental Affairs Bureau. Voice Over Internet
  Protocol. June 2006 (http//www.fcc.gov/voip/)
• Wikipedia. Voice Over IP. March 2007
  (http//en.wikipedia.org/wiki/Voip)
• New Paradigm Resources Group. ISP-Planet.com.
  Executive Summary, VoIP Report 3rd Edition.
  December 2006 (http//www.isp-planet.com/research/
  2006/nprg_voip_summary.html)