The history of broadcasting on the internet, be it of music, video, world events or fashion shows is a short one.

But time on the internet seems to move a good deal faster than in the rest of the world so a great deal has been squeezed into those few short years.

Radio took 30 years to reach an audience of 50 million people, TV took 13 years, but the internet has taken only four. Now the total net population is about 410 million people worldwide.

This is dwarfed by the total potential TV audience of four billion but it is growing fast and webcasting, the transmission of live or pre-recorded programs across the net, is growing with it.

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In 1995 the first audio was streamed over the internet. Now more than 500,000 hours of live programming are broadcast across the net every week. These programs are produced by everything from net-based radio stations to sports events or specialist conferences broadcasting their proceedings.

Most of the audiences for these programs are small, but sometimes a big event draws a big crowd - about nine million people watched Madonna's webcast from Brixton Academy in November 2000.

But the early pioneers of the web would be surprised that audiences of millions watch webcasts that are becoming more commom by the day, largely because the network they built was never meant to be a broadcast medium.

Although initially developed for the military, the network was co-opted by academics to enable them to share research, swap messages and keep up-to-date with all the workers in their respective fields of inquiry, no matter where they were on the planet.

The internet was initially developed for the military

The protocols that keep data flowing across the network split information, be it an e-mail message or an image of Madonna, into small packets which travel by any number of routes to their destination - you.

Once they have all arrived, the message is reassembled and you get to read it, watch it or listen to it.

This works very well for small e-mail messages that you can wait a moment or two for. But it works really badly with large, time sensitive files such as audio and video.

Images or sounds from a concert are recorded in a fixed order and have to be replayed in the same order to make sense.

Sadly it is hard to guarantee transit times across the network of networks that is the internet, so sometimes the chunks of data arrive in the wrong order or get lost en route. This can make the images look less detailed, move jerkily, or distort sound.

Battling bandwidth

The other big problem that anyone staging a webcast must contend with is the fact that most of the people wanting to watch it, you and me, sit at the edges of the internet where bandwidth, the amount of data your phone line can receive, is very low.

In the heart of the network billions of bytes of data can be passed around in an instant. You and me typically have to make do with 56,000 bits per second.

As a result many of the people putting music and video on the web are signing alliances with companies who promise to get this content to consumers.

Typically the data for the webcast is replicated and stored closer, in network terms, to the group wanting to view it. This overcomes the problem of everyone trying to access one site hosting the webcast.

The short supply of bandwidth has meant that novel ways to shrink music or movies to a size that people can download over a phone line are proliferating.

Companies such as Microsoft, Real Networks, Liquid Audio and many others are all trying to establish their software as the best way for people to view web broadcasts or multimedia files on the net.

The programs these companies produce to play audio and video will not play broadcasts formatted using a rival's software.

It is a little like needing a different TV for every channel and means that for the moment net casting looks like it will stay narrow rather than broad.