1. 24/08/2005 IP Telephony1 Guided by: Presented by: Dr.S.K.Ghosh Nitesh Jain 05IT6008 M.Tech 1 st year

2. 24/08/2005 IP Telephony2 CONTENTS INTRODUCTION DIFFERENT TYPES WHAT IS H.323 H.323 COMPONENTS PROTOCOL SPECIFED BY H.323 H.323 CALL ESTABLISHMENT H.323 CONTROL SIGNALING FLOW H.323 MEDIA STREAM & MEDIA CONTROL FLOW H.323 CALL RELEASE CONCLUSION

3. 24/08/2005 IP Telephony3 Introduction Internet telephony uses the Internet protocol to send audio, video an data between two or more users in the real time. IP telephony is the integration and convergence of voice and data networks, services, and applications. The main motivation of development of IP Telephony is the cost saving & integrating new services.

4. 24/08/2005 IP Telephony4 Introduction (cont…) Vocaltec introduced the first Internet telephony software product in early 1995. Running a multimedia PC, the Vocaltec Internet Phone. In 1996, Vocaltec with an Intel Company announced to produce the first IP telephony gateway.

5. 24/08/2005 IP Telephony5 Different Types Of IP Telephony PC to PC Phone-to-phone over IP PC-to-Phone Phone-to-PC

6. 24/08/2005 IP Telephony6 PC to PC Figure 1 (ref: www.iec.com)

7. 24/08/2005 IP Telephony7 Phone-to-phone over IP using Gateways Figure 2 (ref: www.iec.com)

8. 24/08/2005 IP Telephony8 Phone-to-phone over IP using Adapter Boxes Figure 3 (ref: www.iec.com)

9. 24/08/2005 IP Telephony9 PC-to-Phone or Phone-to-PC Figure 4 (ref: www.iec.com)

10. 24/08/2005 IP Telephony10 Different type of IP telephony Standard H.323 standard Session initiation protocol (SIP) Media gateway to media controller protocol (MGCP)

11. 24/08/2005 IP Telephony11 What is H.323 The H.323 standard for the transmission of real-time audio, video, and data communications over packet-based networks based on IP telephony. H.323 is a standard produced by the ITU-T Study Group 16. Currently the most widely-supported IP telephony signaling protocol.

12. 24/08/2005 IP Telephony12 H.323 Components Terminals Gateways Gatekeepers Multipoint Control Units (MCUs)

13. 24/08/2005 IP Telephony13 Terminals : H.323 terminal can either be a personal computer or a stand-alone device, running an H.323 and the multimedia applications. Gateways : An H.323 gateway provides connectivity between an H.323 network and a non-H.323 network.

14. 24/08/2005 IP Telephony14 Gatekeepers Address Translation Admission Control Bandwidth Control Zone Management Call-Control Signaling Call Authorization Call Management

15. 24/08/2005 IP Telephony15 Multipoint Control Units: MCUs provide support for conferences of three or more H.323 terminals. All terminals participating in the conference establish a connection with the MCU.

16. 24/08/2005 IP Telephony16 Protocols Specified by H.323 audio CODECs video CODECs H.225 registration, admission, and status (RAS) H.225 call signaling H.245 control signaling real-time transfer protocol (RTP) real-time control protocol (RTCP)

17. 24/08/2005 IP Telephony17 H.225 RAS Gatekeeper discovery Endpoint registration Endpoint location Admission control

18. 24/08/2005 IP Telephony18 H.225 call signaling H.225 call signaling is used to set up connections between H.323 endpoints over which the real-time data can be transported. Two types : –Direct call signaling –Gateway routed call signaling H.245 Control Signaling Capabilities Exchange Logical Channel Signaling

19. 24/08/2005 IP Telephony19 Real-Time Transport Protocol Real-time transport protocol (RTP) provides end-to-end delivery services of real time audio and video. RTP is used to transport data via the user datagram protocol Real-Time Control Protocol (RTCP) RTCP provides control services for RTP.

20. 24/08/2005 IP Telephony20 H.323 Call Establishment Figure 5 (ref: www.iec.com)

21. 24/08/2005 IP Telephony21 H.323 Control signaling Flows Figure 6 (ref: www.iec.com)

22. 24/08/2005 IP Telephony22 H.323 Media stream & media control flow Figure 7 (ref: www.iec.com)

23. 24/08/2005 IP Telephony23 H.323 Call Release Figure 8 (ref: www.iec.com)

24. 24/08/2005 IP Telephony24 Conclusion Internet telephony is cost savings and integrating new services. Internet Telephony is a powerful and economical communication options by combination of the telephone networks and data networks. Many public telecommunication operators are establishing their own IP telephony services, and using IP-based networks as alternative transmission platforms.

25. 24/08/2005 IP Telephony25 References : Book on “IP Telephony“Olivier Hersent, David Gurle & Jean-Pierre Petit. www.iec.org/online/tutorials/ www.cis.ohio-state.edu/~jain/ www.cs.columbia.edu/~coms6181/ www.cisco.com/ www.tmcnet.com/ www.javvin.com/

26. 24/08/2005 IP Telephony26 THANK YOU ?