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Ctc final presentation skype t5_yuzhao li (u3035801)






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    Ctc final presentation skype t5_yuzhao li (u3035801) Ctc final presentation skype t5_yuzhao li (u3035801) Presentation Transcript

    • Made by: Yuzhao Li
      Student ID:u3035801
      Skype A case study of VoIP applications
    • How many of you are using Skype, or have ever used Skype?
      Do you know what the VoIP is?
      Warming-up questions
    • Voice over Internet Protocol
      A general term for a family of methodologies, communication protocols, and transmission technologies for delivery of voice communications and multimedia sessions over Internet Protocol networks, such as the Internet.
    • People’s voice or other sounds record by the computer as samples
      Then the samples are send as packets over IP network to another computer and played there.
      How does VoIP work
    • Different from traditional Public Switched Telephony Network, VoIP has several advantages
      Cost saving
      Better voice quality
      Advantages of VoIP services
    • A software application that provides telephone service using VoIP technology facilitating voice communication over the internet.
      Available free for both PC and Macintosh platforms as well as Linux and pocket PC’s
    • Founded in 2003 by the Swedish entrepreneur Niklas Zennstro, and a Dane Janus Friis
      In October 2005, eBay purchased Skype
      In October 2006, Skype 2.0 for Mac was released
      In 2009, Skype 4.0 was released
      On October 14 2010, Skype 5.0 for Windows was released with a slew of improvements and feature additions
      History of Skype
    • Usage and market share
    • Skype offers a number of features to its users, such as:
    • Rate control mechanism
      Voice codec
      Error-resilience mechanism
      Better relaying mechanism to go through NAT servers or firewalls
      Reasons of Skype improvement
    • Can find and locate users
      Highly scalable
      Strong NAT/ firewall traversal capability
      Security feature
      Integrated buddy list, presence information, chat, and audio conferencing
      Highlights of Skype
    • Quality of service
      Susceptibility to power failure
      Still difficult to make a emergency calls
      Lack of redundancy
      The security issues
    • MSN sends smaller packets with higher sending rate than Skype
      MSN has higher variance in packet’s inter-arrival time while Skype sends packets in a stable fashion
      Skype has better performance than MSN in MOS score
      Skype can increase its throughput to recover missed data when suffering from higher loss rate, but MSN can’t
      Skype has better mechanisms to go through NAT than MSN
      Skype vs. MSN
    • Clarity
      Can call any phone, local or international, not just computers
      Quality of voice
      Have many different options
      Why people use Skype?
    • Skype have a lot of impacts on its users, and also may influenced people’s daily life.
      For example, its impact on teaching and learning.
      It opens up numerous options to teacher and students interactions and the Skype offers can potentially revolutionize the teaching and learning process. So that teachers can envision students exchanging ideas, cultures, and information using the free Skype to Skype feature from one classroom to another or one student to another.
      Impacts on users
    • Weicheng Xiao. (2006). A performance Study of VoIP Applications: Skype vs. MSN. National Taiwan University
      LaniRexius. (2007). Skype- An Emerging Technology. London: Oxford University
      About Skype. (2010). Retrieved October 26, 2010. from http://about.skype.com/
      History of Skype. (2010).Retrieved October 26,2010. from http://en.wikipedia.org/wiki/Skype
    • Thank you for listening!And hope you enjoy this presentation!