SHREEJEE INSTITUTE OF TECHNOLOGY AND MANAGEMENT

Internet Telephony

• Guided By:- Mr. Prakash Singh Panwar

• By:- Abhishek Mahajan• EC BRANCH 1ST YEAR

INTRODUCTION

Internet telephony is a powerful and economical communication option by combination of the telephone network and data networks.

Internet telephony uses internet to send audio between two or more computer users in the real time, so the the user can converse vocal Tec introduced the first internet telephony software product in early 1995

The factors which are making internet telephony possible

voice quality is increasing thanks to new codec technology.

There are on going improvements in compression techniques.

Full-duplex PC sound cards enable two way simultaneous calls.

The typical PC is getting more & more powerful, making it possible processor-intensive functions without specialized hardware.

How internet telephony works? In one side gateway connects to the telephone word.

It can communicate with any phone in the world.

On the other side, the gateway connects to the Internet world. It can communicate with any computer in the world.

The gateway takes the standard telephone signal, digitizes it, compresses it, packetizes it for the Internet using IP protocol and routes it the destination over the Internet.

GENERATION OF INTERNET TELEPHONY

• The first generation :-Introduction to enable voice conversations user with telephony software-equipped-computers.

• The second generation:-it overcomes the difficulties with PSTN interfaces protocols and mapping IP address.

• The third generation:-internet telephony starts to receive serious attention. These gateways provides a two-ways interfaces between the PSTN and internet.

INTERNET PROTOCOLS

IP packets are forwarded across the network by routers

IP Routers do best-effort routing

Voice signals can be prioritized using priority queues

RTP and RTCP keep end points informed of transmission quality.

Call set up is done using Session Initiation Protocol (SIP) or something similar

VOICE OVER INTERNET TELEPHONE

• VoIP tries to let go voice (mainly human) through IP packets.

• VoIP works like that, digitalizing voice in data packets.

• Voice (source) - - ADC - - - - Internet - - - DAC - - Voice (dest)

Public switched telephone network (PSTN)

• A synonym for traditional circuit-switched telephone networks offered by public telecommunication operators (PTOs), as well as integrated services digital networks (ISDN), and public land mobile networks (PLMN).

WHAT AN IDEAL INTERNET TELEPHONY

• High volume call processing within and between public and private networks.

• High volume real-time translation between IP and switched networks.

• Economic scalability.• Broad acceptance and implementations of

standards

INTERNET TELEPHONY HARDWARE REQUIREMENT

• PC 386 or more & Sound card.• Full duplex capable .• A network card connected with internet.• Hardware accelerating cards .• Quicknet PhoneJack • Quicknet LineJack • VoiceTronix V4PCI • VoiceTronix VPB4 • VoiceTronix VPB8L

ADVANTAGES• In VoIP mechanism you can talk all the

time with every person you want (the needed is that other person is also connected to Internet at the same time), as far as you want (money independent) and, in addition, you can talk with many people at the same time.

• Exchange audio data with people and also simultaneously sending images, graphs and videos.

DISADVANTAGE• Integration between VoIP architecture and

Internet. voice data communication must be a real time stream (you couldn't speak, wait for many seconds, then hear other side answering): this is in contrast with the Internet

• Heterogeneous architecture that can be made of many routers (machines that route packets),which has a very high round trip time (RTT), so we need to modify something to get it properly working.

WHAT THE USER GET NOW

Point to multipoint voice.Data conferencing.Application sharing.Long distance telephone saving.

IMPACT ON THE IT MARKET

• Will IP Telephony be able to cut cost?• Ans:-It depends on the organistions ability to

reduce the costs associated with infotech personnel, network equipment and the transmission services.

INDIAN DIASPORA

• In Indian context we need to cut the costsfor the people to be enabled to connected to

the world and change the living styles.

SUMMARY• Business acceleration in this century is directly

related to the success of IT organization's ability of giving a competitive edge

• Convergence of all communication traffic onto a packet network