IP telephony Evolution or revolution

1. IP telephony Evolution or revolution Jan Damsgaard Dept. of informatics Copenhagen Business School http://www.cbs.dk/staff/damsgaard/

2. Agenda • IP telephony • IP telephony as evolution • IP telephony as revolution • VoIP WLAN technology J. Damsgaard, 2004

3. IP Telephony • Circuit switched Vs. Packet switched • IPv4 og IPv6 • Address space from 232 to 2128 • Or one address per square inch on earth Kilde: www.pcworld.dk J. Damsgaard, 2004

4. Soft Vs Hard IP telephony • Hard IP • Box inserted between ordinary phone and broadband Internet connection (adsl or cable modem) • Stationary use – easy move of box • Maturing of existing technology. You can call everyone • Soft IP • Software application that is installed on the computer which has to be running and connected to the Internet • Mobile use – wireless access • You can all all other users running the same program and if you kow their alias. J. Damsgaard, 2004

5. IP telephony as evolution • Automation of existing services • Usually it is the teleoperator that installes and operates hard IP telephony • Drives prices down faster • The existing fixed net is used as analogy and IP telephony does not affect the provision of other services J. Damsgaard, 2004

6. IP telephony as evolution • All communication through the same net • Integration of data, sound and images • Relocation becomes easy • From place to place (net-plug) • Wireless phones • Globally • But also from work to home • Voicemail can be sent as attachment to email J. Damsgaard, 2004

7. IP telephony as revolution • Here is a radical departure in the provision of services and the way it is priced • The computer is used as a phone • With speakers and a microphone • The Internet is used as medium • VoDSL (Voice over Digital Subscriber Line) • QoS a problem? (64 kbit/s) J. Damsgaard, 2004

8. Skype • Skype is a piece of software that enables free telephone conversations from anywhere to anywhere • You do not pay per minute or more the longer distance • Teleoperator cut out of the loop • Skype uses P2P (peer-to-peer) technology where an Instant messenger is combined with telephony • Skype is created by the people behind KaZaA http://www.skype.com/ J. Damsgaard, 2004

9. The best from both worlds • RTX has developed a wireless IP telephone • Contrary to most other phones the new RTX phone has two jacks. One for the Internet and one for the PSTN. I.e. you only need one phone and it bridges the two worlds • The wirless RTX phone can run a Skype Client • The wireless phone connects through the WLAN • Voila – a VoFi (802.11x-enabled VoIP) telephone Kilde: www.computerworld.dk J. Damsgaard, 2004

10. And there is more coming • Motorola and NEC collaborate to develop an IP telephone that can roam from a WiFi hotspot to the GSM network without loosing the IP address • Motorola’s components include a WiFi enabled mobile phone and a "mobility manager” that manages the hand over between a WLAN and the public mobile network J. Damsgaard, 2004

11. And it does not stop • Community based WLAN VoIP • Users shift from being passive consumers of telecommucation services they become active providers of telecommuncation services • Imagine that your WLAN together with your neighbour’s WLAN become small pieces of a giant telecommunication infrastructure that in comparison to 3G is much faster • Teleoperators become bit pipes J. Damsgaard, 2004

12. We have never been mobile • Only serial stationary • We move in steps and therefore we do not need broadband while in transition (exceeding 64 kb/s) • WLAN at work, in the home, at the gasoline station at the mall • But not between them • This is good news for WLAN and bad news for UMTS J. Damsgaard, 2004

13. 802.11x Standards J. Damsgaard, 2004

14. WLAN broadband • Clusters of public and private WLAN Overlaping but closed WLANs Overlaping open WLANs J. Damsgaard, 2004

15. Tragedy of the commons • Hardin (1968) describes it as a situation in which too many actors have privileges to consume a common resource leading to its overuse and eventually collapse. • The tragedy of the commons has been described as a social trap because behavior that gratifies the individual in the short-term has long-term collective costs • For example, every fisherman has the incentive to maximize her current harvest, while the carrying capacity of the fish stock is limited. Therefore, if fishermen combined harvest at a higher rate than the fish can reproduce, the resource will soon be exhausted • This behavioral pattern locks in the individual in a scheme that is destructive for the common resource. In the long term the individuals therefore become victim of their collective actions. Hardin, Garrett (1968). “The Tragedy of the Commons” Science, December, 13. 1243-1248. J. Damsgaard, 2004

16. Causes and Counter Measures

17. So what • Moores law • Double the capacity every 18 months • Makes the tragedy of the commons to a purely theoretical discussion • Napster and KaZaA • Supercows that eat any available piece of grass Source: http://www.intel.com/research/silicon/mooreslaw.htm

18. Conclusions • IP telephony is the future • Either as evolution or revolution • Convergence of GSM/GPRS/UMTS/WiFi/UWB/BT into one mobile unit (integrates PDA/Telephone/Data etc.) • Dynamic shift between available resources • Maybe even auction J. Damsgaard, 2004