Using a piece of software intended for network voice conferencing, I had a real-time conversation across the Internet last week, in effect "phoning" a computer at the University of Illinois in Chicago (from here in Syndey, Australia) and chatting with the person at the other end.

The total cost? For our half-hour chat, it was $5.25 - 25 cents for the local phone call to national Internet access provider Oz-Email in St.Leonards, plus their online charge ($10 an hour during business hours).

While the link was not as good as a phone call, going through the phone system would have cost nearly $38 for the same period of time.

Telecom effectively became a wholesaler as we used the Internet to communicate across the Pacific over a series of connections which ended on the university's Urbana-Champaign campus at a Power Macintosh computer owned by Charley Kline, the man who wrote the software - called Maven, for Mac Audio Visual.

We used Macintoshes because of the high quality of the sound processing equipment (16-bit stereo) integrated into the Mac platform.

``I am really pleasantly surprised,'' said Kline, as the link was established by typing his machine number, or Internet Protocol address, into the "new session" field of Maven after dialling into Ozemail.

After intending to connect at 28.8 kilobits a second using the maximum speed of NetComm's SmartModem M11F, we accidentally went in at 14.4  but still found we could hear Kline perfectly—though he later commented that he had to cup his hands over his ears to hear us at this point.

When the modem was wound up to its natural 28.8, with compression gaining us a likely 40-50 kbs, the connection was good  both ways.

Kline, 30, the campus area network architect at Urbana-Champaign, home of the World Wide Web browser, Mosaic, had agreed in an e-mail message to "test the total network bandwidth between you and me", but was not sure if a 28.8 modem at our end would be sufficient.

"The lowest bandwidth codec, delta-mod, requires a constantly 17 kilobits per second or so," he had said. "This MAY be within the ability of a v.32bis modem, but I wouldn't want to make any guarantees."

On the day, at 9.30am Sydney time and 4.30 pm in Chicago, we were all surprised. Kline said the reason for the success was that "the compression on the modem was doing a good job for us". The top-of-the-range NetComm SmartModem uses 16-bit technology and was pumping through the packets of sound at between 40 and 50 kilobits a second.

With our voices floating across the Internet as clear as a bell, there was laughter and some comments about putting out of business "Ma Bell and the Baby Bells" (the first US monopoly phone company and the competing companies spawned after deregulation).

We made minor adjustments to the settings in the software, and talked about how the future might look in a more stable Internet, with greater bandwidth available.

"I think that what we're doing here and what the other people working on audio and video transport are doing will certainly have a great impact," Kline said. "But the lifetime of software is very short, so I don't look at Maven per se as carrying us into the next generation of how people communicate - but it's certainly one of the steps along the way."

Commenting on the low-cost "call" using computers and high-speed modem, Telecom Australia spokesman, Mr Tim Lloyd-George, said the easiest way to call the US was still to pick up the phone.

Voice-through-computer communication would be limited to the "techno-hobbyist" for some time to come, he said.

"The Internet in Australia is still Telecom, because the line is leased from us, so we're still there in a wholesaling capacity. These days Telecom is a mixed wholesale and retail business," he said.

Lloyd-George quoted technical experts within Telecom as saying the sort of success achieved with the computer voice chat to Chicago would be possible only rarely because of varying bandwidth availability on the Internet.

"It's definitely a minority sport, and not the way to go just yet," he said.

In response to scepticism about the likelihood of continued success of such "calls", I repeated the experiment last Saturday night, this time linking up with German computer science student Kai Strieder, 25, who had messaged me on Internet Relay Chat (a place where thousands of people have live conversations via text keyboarded into a "channel").

The quality of the conversation with Strieder, who was on a Macintosh IIvx at the University of Dortmund in the Ruhr Valley, was not as good as that with Kline. Some sentences dropped out. But on this occasion I was using a PowerBook Duo 230 subnotebook with a 68030 processor, rather than the Centris 610 with the more powerful 68040 processor used for the call to Kline.

Kline said phone-quality speech is the target of new algorithims being developed for Maven. These require lower bandwidth, but higher processor speeds such as those now available only on the Power Mac.

He said Maven was the voice component of Cornell University's video-conferencing software, CU-SeeMe, being written for PC as well as Mac. Beta versions of the PC software are now available on the Internet.

Several weeks before finding Kline's e-mail address and seeking his help, I had been given a copy of Cu-SeeMe by someone on the #macintosh channel on Internet Relay Chat. He sent the software in a few minutes using DCC (direct client-to-client file transfer) .

After double-clicking the icon and typing in the address of a reflector site - a sort of video broadcasting channel - I had picked up a talk being given by a NASA spokesman to the Macworld exhibition at Darling Harbour. The sound was barely audible, and the video patchy and slow. But the fact that the image of a man was moving around in a window in the corner of my screen was startling to say the least.

But what of the PC platform? Cornell University, in association with Illinois, was committed to making both audio and video run effectively under Windows, Kline said.

"Audio on the PC is not nearly as well-developed as the Macintosh audio, unless you've got the famous SoundBlaster card. PCs generally don't come with very good audio-processing hardware and certainly not with very good audio processing software - it's not integrated into the operating system like it is on the Macintosh.

"Thre's so much help on the Mac. You can create multiple sound channels and write audio for all of them and the operating system takes care of mixing them all together into the final product. It's sort of built-into the Mac," he said.

"But certainly we do need to get Maven running on the PC platform. It's going to be harder to develop, and it will be a completely different animal I can guarantee you that."

Maven was developed to its current state - the latest version, called 2.0d23 - three months ago after a "proof of concept" had been written in 1992.

"The whole thing came out of the fact that an audio video transport working group told me that the only serious platform for multi-media was a high-end Unix workstation," Kline said. "I though that was silly, because I could do it on a Macintosh."

"The first version was just to prove I could do it. Then as the algorithims started coming out of this working group and I did a little research on my own, the first incarnation of the version that we are using now came out, and I just made improvements on that code up to version 2.018.

"The latest version was done by Eric Scouten, a graduate student who's a very good Macintosh person who's made a lot of enhancements, and who is converting it to the Code Warrior plaform (the PowerPC)."

Kline said that software such as Maven would bring people closer together globally - "you and I were talking esentially in real time and sometimes we had to strain to hear, but we were basically talking across the globe using data packets, and this will have a great impact."

Would the Internet ever develop to the point that it was a reliable medium for voice and video between computers? - "The answer to that question is just money. All the technology exists to make the Internet run as fast as we want it to. It's just very expensive stuff. In the long haul it's either fibreoptic links or microwave. Coaxial doesn't carry the required bandwidth over the kind of distances you need to built up a national network."

Kline said it the market demanded multimedia, voice and video over the Internet "then we'll pay for it, and the money will be there."

Thomas Liddle, a reporter with PCWEEK in Sydney, is Australia's first Internet columnist. His Adventures on the Internet column is published monthly in PCWEEK's sister publication, PC User. He is also a guest speaker at cyberspace seminars and an Internet writer for Australian MacWorld. This article was first published in The Sydney Morning Herald and The Age, Melbourne, last month.

  The Technical Stuff

The voice links between Sydney and Chicago were made with Maven, the lastest version of which (2.0d23) can be downloaded from the home page of the author, Charley Kline, on the World Wide Web at http://tampico.cso.uiuc.edu/~kline/ cvk.html.

Maven needs the Sound Manger extension, which is has been included with the Macintosh operating system since version 7.1. Earlier versions of System 7 need Sound Manager 3.0.

Macintosh computers with a 68040 Motorola processor or greater are recommended for best results. The link with Kline was made with a Macintosh Centris 610 owned by Clive Clelland, of Oz-Email.

The connection was made using the shareware program, MacPPP, to establish a point-to-point link through a special 28.8k Microcom modem line (the normal lines are linked to 14.4 kilobits per second modems) set up by Oz-Email.

Our Centris used a NetComm SmartModem M11F with a 16-bit processor.

To run Maven, you open a new session and type in the machine number or name of the machine you're dialling (or your opposite number can type in yours). Your IP address is located on the outside panel of your MacTCP control panel. Then adjust the settings as follows:

Under the audio menu, both parties should set the encoding to delta-mod, and qantization to 160 ms. Encoding tells Maven how to encode the sound samples into packets as they come out of the analogue phone line to enter the digital converter.

Quantization controls how many of the audio samples Maven will gather up into a packet before sending the packet out on to the network. We sent one packet every 160 milliseconds - a kinder way of treating the Internet than it we had been hogging one packet every 20 milliseconds. However, over the distances involved the difference would not have great.

Kline's team is working on codecs (coder-decoders), or algorithims that model the human voice more closely for accurate transmission.

"We can have the sending side try to figure out what the vocal tract is doing and model it as a full voice synthesiser and send the synthesiser parameter over the network," he said.

"That way we can get a very low network bandwidth. Some of the nice ones that we're working on now can do what we were doing in fact at better quality for about 4800 bits per second.

"That's quite nice, but you pay a huge price in terms of CPU time, and I don't think these new codecs would work on anything other than a Power Mac."