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Sci Tech
Say `hello' — via Net telephony!
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This week, India joins other Internet-enabled nations to allow its citizens access to Net-based telephony. Anand Parthasarathy examines what this means for the average user and what is required by way of new hardware and software to exploit th e technology of Voice over Internet Protocol.
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IF YOU stop and think for just a minute, using the Internet to make telephone calls must be the most roundabout, clumsy, misuse of technology, ever conceived — akin to reaching all the way around your head, to touch your nose. Consider the steps involved:
First: You take what is basically a system to carry continuous (or analogue) voice signals — the plain old telephone system or POTS.
Second: You use it to carry your traffic to and from the World Wide Web — which is a lot of coded ones and zeroes. In order that this digital signal stream can ride on the back of the analogue telephone line, you first `modulate' it — that is, convert it into a continuous signal.
Third: At the other end, you have to `demodulate' the signal to recover all the digital ones and zeroes in the right order. The device that does this constant MOdulate-DEModulate conversion is the modem, at each end that one latches on to the PC. This is great as long as you want to send text, pictures etc, all suitably digitised. Then someone thought, why not I use this digital bit stream to carry voice as well?
Fourth: You therefore speak into a microphone, attached to your PC and use software which then chops your sound into manageable chunks, converts each into a digital word and sends it as data down the telephone line.
Fifth: At the other end, this digital data is unscrambled and the loudspeaker at the recipient's PC reproduces something resembling your voice. If he or she wants to reply and provided both ends have installed the identical software, one goes through these five conversions all over again.
The irony is that all this is done using a line that basically works quite well as a carrier of voice thank you! Then why all the excitement about the Indian Government's decision from April 1, to legalise Internet Telephony and allow all Internet Service Providers, if they so choose to offer the facility to their customers? It's the cost, stupid!
The key to the attraction of using the Internet to initiate and terminate telephone conversations is that getting on to the Net is cheap: If you have an Internet account, logging on only costs the price of a local call. Once on line, the Internet, being the great democrat that it is, doesn't differentiate between your friend in the next house — and another on the next continent. So as long as you have the hardware and software to exploit the Internet's telephony features, you could make a call to the US or Australia at the same price of a local call.
What makes it possible is Voice over Internet Protocol (VoIP), the method by which voice is converted into data, sent through the Internet to another PC on the Net or even to a stand-alone telephone somewhere else where it is converted back into a voice signal.
This ability of the Internet Protocol or the IP as it is known, to sustain a voice communication was first exploited almost exactly seven years ago this week by an Israeli company called VocalTec, when it released a free software to make this happen. Those guys at VocalTec are the ones we have to thank today.
While we are in the ``thank you'' mood let's not forget two national agencies whose attitude has been crucial:
- The U.S. Federal Communications Commission (FCC) that nation's telecom watchdog, responded in 1996 to the yelps of outrage from American traditional telecom providers, and strong pressure to ``ban'' VoIP software like VocalTec, by taking a historic decision NOT to interfere in the processes of technological shakeout in the Internet telephone arena. William Kennard, a former FCC Chairman articulated the Commission's sane view that ``government must not regulate against problems that were yet to materialize in a market yet to develop, based on a technology that no one yet understood.''
-The response of the Indian government's monopoly providers of Internet access, in the early years was the exact opposite of this pragmatic position. VSNL customers in 1998 were warned ``not to use the Internet connection for telephony or fax applications'' on pain of being ``permanently debarred from using Internet services''.
The Nigam went so far as to block the websites of agencies like VocalTec, Net2Phone and NetSpeak, who provided free Net Telephony software or diallers. Fortunately saner counsel prevailed and ever since the ministries of Information Technology and Telecommunications were combined with Pramod Mahajan as the Union Minister in charge, a clear roadmap to enable Net Telephony was announced.
A week or so before D Day, April 1, 2002, the Ministry announced guidelines for the new Net-Phone sangam. Here too the telecom regulatory authority (TRAI) seems to have a taken a view that may turn out to be historically farsighted: it has accepted that all existing ISPs (who register to do so) can offer Internet Telephony as an inherent part of their service, without any additional licensing.
However the connected government notification of March 21 is hedged in with a few riders. It is now legal to offer Net-based telephony:
- from a PC to PC ( any where in India or abroad)
- From a PC in India to a telephone outside India only
- From Internet protocol-based terminal in India to similar terminals abroad.
What this means, is that your Internet Service Provider (VSNL, Satyam, Dishnet, HCL Infinet or who ever) can provide an additional service, at a small fee, whereby you can dial from your PC and make an international call to any telephone number abroad. However such a service provider cannot offer you a similar service to call long distance within India — which would be like making an STD call from your PC. The third option means that instead of going to the corner ISD booth, you may soon be offered the option of placing your international calls from special Internet Telephone booths which uses the Internet Protocol to carry the call, rather than the conventional telephone circuits which are known as Public Switched Telephone Network (PSTN).
Calls from such IP enabled international telephone facilities are expected to see a drastic fall in the price of ISD calls — a call to the US which presently costs about Rs 50-60 per minute may cost about a fifth to a tenth of this by the IP route. Indeed, many international calls made by using competitively priced pre- paid cards which use a toll-free access number may (though you don't realize it) be converting your voice call into an IP packet and sending it the cheap way!
In all this hardly, any one is talking about the actual quality of telephone calls via Internet. By the time the sound emerges from the `chakravyuha' of analog to digital conversions, it can be anything from bearable to very bad. Also, there will be perceptible delay (typically 50- 200 milliseconds) while the Internet handles the `packets' of voice information and switches it through the various gates in the chain of computers.
This is quite disconcerting — except to radio hams and others who are used to conducting wireless conversations using `press to speak' transmitters.
While the ISPs in India are getting their act together and readying to offer their value added Net-based telephone services, can you as an individual PC user and Internet account holder, get a feel for how Internet telephony works? Yes indeed! And at very minimal cost.
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