1. National Institute of Science & Technology TECHSEM PRESENTATION 2004 Tanusri Panda Under the guidance of pradeep kumar jena Presented by Tanusri Panda(IT200157331)

2. National Institute of Science & Technology TECHSEM PRESENTATION 2004 Tanusri Panda [1] Introduction to IP Telephony Concept of IP Telephony Advantages and Challenges Business Aspects of IP Telephony Users of IP Telephony Security Issues Applications and Vendors Overview

3. National Institute of Science & Technology TECHSEM PRESENTATION 2004 Tanusri Panda [1] The current development on telecommunication industry is changing the use of telecommunication networks remarkably. People use telephone lines more and more for data transfer instead of ordinary voice calls. Obviously these changes has strong affection to the networks and operators.Public networks are moving from circuit switched networks to packet switched networks.This will cause telecommunication network and data communication networks which are mainly IP based. IP telephony means that voice and fax calls are transmitted over an IP network such as an Internet,rather than over the familiar PSTN. Introduction

4. National Institute of Science & Technology TECHSEM PRESENTATION 2004 Tanusri Panda [1] During last four years IP Telephony has become a hot topic.IP Telephony means transmission of voice over IP network. The basic steps for transmitting voice over IP network are:- 1.Audio from microphone are converted at audio I/p device. 2.The samples are copied in to the memory buffer in blocks of frame length. 3.Silence detector decides whether the block is to be treated as silence or as a part of a talks port. CONCEPT OF IP TELEPHONY

5. National Institute of Science & Technology TECHSEM PRESENTATION 2004 Tanusri Panda [1] 4.if the block is talks port it is coded with a selected algorithm. 5.some header information is added to the block. 6.The packet is transferred over a physical network and received by the peer. 7.The header information is removed,block of audio is decoded using the same algorithm it was encoded, and samples are written into a buffer. 8.The block of samples is copied from the buffer to the audio o/p device. 9.The audio o/p device D/A converts the samples and output them.

6. National Institute of Science & Technology TECHSEM PRESENTATION 2004 Tanusri Panda [1]

7. National Institute of Science & Technology TECHSEM PRESENTATION 2004 Tanusri Panda [1] The primary difference between the Internet and the PSTN is their switching architectures. The internet is dynamic routing(based on non- geographic addressing) versus the PSTN uses static switching(based on geographic addressing). PSTN dedicates a fixed amount of bandwidth for each conversation and thus quality is guaranteed. When a caller places IP Telephony call,she picks up the phone and hears a dial tone from the PBX if one is available.then she dials the number which is forwarded to the nearest IP Telephony gateway located between the PBX and TCP/IP network. IP Telephony Vs.PSTN

8. National Institute of Science & Technology TECHSEM PRESENTATION 2004 Tanusri Panda [1] Advantages of IP Telephony include lower cost long distance and reduced access charges,more efficient backbones and compelling new services. The benefits of shifting traditional voice onto packet networks can be reaped by businesses,Internet service Providers (ISP),traditional carriers etc. For consumers IP Telephony started from inexpensive or even free internet calls.Many households have only one telephone line which is often used of Web browsing. Therefore they would like to use IP telephony as a way of accepting incoming calls by rerouting them to PC. Advantages of IP Telephony

9. National Institute of Science & Technology TECHSEM PRESENTATION 2004 Tanusri Panda [1] There are three basic business scenarios for IP telephony: IP terminal to IP terminal:- IP terminal to Phone or Phone to IP terminal:- Phone to Phone:- Business scenarios of IP Telephony

10. National Institute of Science & Technology TECHSEM PRESENTATION 2004 Tanusri Panda [1] IP telephony requires new technology into networks : Logical networks and protocols. Logical network elements are needed for call management routing,storing call information,etc and signaling protocols are responsible for billing,security,directory services etc. One of the vital issues for wide spread use of IP Telephony is to achieve international standards and several organizations are IP telephony standards.like ITU- T,IETF,INOW! and MIT. Two Signaling protocol standards exist for IP telephony:ITUS H.32x series and SIP. H.323 seems to have Quite good position at current market compared to SIP. Technical Aspects of IP Telephony

11. National Institute of Science & Technology TECHSEM PRESENTATION 2004 Tanusri Panda [1] The network architecture consists of four types of network elements:Terminals,Gatekeepers, Gateways and Multipoint Control Unit(MCU). Network architecture of H.323

12. National Institute of Science & Technology TECHSEM PRESENTATION 2004 Tanusri Panda [1] Terminals:-these are clients which are able to receive or initiate calls.They generate and receive bi-directional real time information streams. Gatekeeper:-It manages a so called Zone,which is a collection of terminals,gateways and MCU.Gatekeeper may also provide call control signaling,call authorization and call management. Gateways:-It is responsible for connecting IP telephone network to other type of networks,PSTN or ISDN. MCU:-Consist of multipoint controller and a number of Multipoint processors.The Mc handles control info and MPs handles the streams.

13. National Institute of Science & Technology TECHSEM PRESENTATION 2004 Tanusri Panda [1] The internet is an open network where everyone can receive and transmit packets relatively easily. Four basic security aspects are addressed in IP telephony:- Authentication:A process to ensure that the participants really are who they claim to be. Integrity:A process to ensure that the contents of the packet remains unchanged during transmission. Privacy:-Using ciphering mechanisms eavesdroppers are prevented to listen the contents of transmitted packets. Non-repudiation:-A process to prevent that someone can deny he or she done something. Security issues

14. National Institute of Science & Technology TECHSEM PRESENTATION 2004 Tanusri Panda [1] Quick nets specialized Soundcard The internet phone JCK is an audio card developed by Quick net.It is designed specially to carry voice over the Internet or Intranets.It can work with existing soundcard in multimedia PCS. Nokia Solution Nokia offers a range of IP telephony clients and peripherals for end-users that enable different services over IP networks like: 1.IP courier Ethernet Phone 2.My.way IP Telephony Client Application 3.Phone.way serial Telephony Adapter Application and Vendors

15. National Institute of Science & Technology TECHSEM PRESENTATION 2004 Tanusri Panda [1] Technology is developing very fast.In the future,there will be many diff kind of IP telephones popping out. The following list few properties that future IP Telephony terminals should have: Multi-functionality:-they can act like phones, pagers, credit cards,notepad etc. Mobility:-they can be used to access wherever the user is. Design:-they must look and feel good. Price of the advanced equipment must be low. Future Equipment

16. National Institute of Science & Technology TECHSEM PRESENTATION 2004 Tanusri Panda [1] VOIP in its various forms raises several complex questions that go beyond the immediacy of whether or not consumers get cheaper telephone calls, but at the same time IP technology is ushering in a world of peer- to-peer communications that provides opportunities (and dangers) for multiple business models and players. IP telephony terminals can be entertainment center in the future. Radio and Video services could be used over IP network from home or even when the user is traveling by using mobile phones Conclusion

17. National Institute of Science & Technology TECHSEM PRESENTATION 2004 Tanusri Panda [1] THANK U