Tutorials Streaming

Rob Glaser: Streaming, Badly, Over a Dial-Up Modem

By Infinite Creation · Profile

At a Glance

Rob Glaser (born 1962) founded Progressive Networks, later RealNetworks, and shipped RealAudio in 1995: the first widely used system for streaming audio over ordinary dial-up internet connections. The quality was poor and the significance enormous: it established that media could be delivered as it played, rather than downloaded first.

Born 1962, United States
Anchor year: 1995, RealAudio
Strand: canon

Career

The problem as it stood

Audio and video on the early web had to be downloaded completely before playing. A few minutes of audio over a 14.4 kbit/s modem meant a wait of many minutes, which made the internet useless as a medium for anything time-based.

What he actually did

RealAudio combined aggressive low-bitrate speech-oriented coding with buffering and a tolerance for imperfection: play as the data arrives, buffer against jitter, and accept dropouts rather than stopping. RealVideo followed.

How it worked

Streaming trades quality and reliability for immediacy. A buffer of a few seconds absorbs network variation. If the connection cannot keep up the audio degrades rather than halting. That trade, accept a worse experience in exchange for starting now: is the founding assumption of every streaming service since.

What it made possible

Internet radio, and the demonstration that made everything after it plausible. Adaptive bitrate streaming, and eventually HLS and DASH, are refinements of the same trade with vastly more bandwidth available.

What happened to him

RealNetworks was dominant in streaming media in the late 1990s and was overtaken by Windows Media, QuickTime and then by Flash and HTTP-based streaming. He remained involved in technology and in political and philanthropic work.

Where the credit landed

Glaser is credited within the industry and is a slightly awkward fit for this corpus: his contribution is a product and a business rather than an invention, and RealNetworks is remembered as much for intrusive software as for the breakthrough. But the founding demonstration is real, and the fact that it sounded bad is central to why it mattered.

Known For

Streaming trades quality and reliability for immediacy: that is the founding assumption.
A few seconds of buffer absorbs network variation.
It sounded terrible, which is precisely what made the point.

Knowledge Base

What You'll Learn

The important demonstration was not that it worked well but that people accepted it.

Buffer, latency and the trade nobody escapes

A larger buffer absorbs more network variation and adds more delay before playback starts. That trade has never gone away: a live sports stream running thirty seconds behind broadcast is paying exactly the same tax RealAudio paid, with more bandwidth and better codecs. It is also why streaming still cannot match broadcast for genuinely live events, thirty years on.

Where This Fits

RealAudio streamed over dial-up, the first internet transmission link in the chain covered in A History of Broadcast Technology.

FAQ

Q: What was RealAudio?
A: The first widely used streaming audio system, launched in 1995, which played audio as it arrived over ordinary dial-up connections instead of requiring a complete download first.

Q: Why does streaming still lag behind live broadcast?
A: Because streaming buffers to absorb network variation, and buffering means delay. Broadcast transmission has no equivalent requirement.

Vocabulary

Streaming. Playing media as it arrives rather than after a complete file has downloaded. Requires the delivery rate to keep pace with playback, which is why it was hard on early connections.

Buffer. A store of data received ahead of the playback point, absorbing variation in delivery speed. A larger buffer survives interruptions better and delays the start of playback.

Dial-up bandwidth. The very limited data rate available over a telephone line, measured in kilobits per second. The constraint that made early streaming a problem of extreme compression rather than of delivery.

Rebuffering. The interruption when the buffer empties and playback stops to refill. The most visible failure in streaming, and the thing adaptive delivery schemes exist to avoid.

Sources

No document is cited here. Checked 20 August 2026.

RealAudio shipped as a product in 1995 rather than as a specification or a paper, and no patent naming Glaser could be found from here. The protocols that carried it were proprietary, which is part of why the approach was later displaced by HTTP based streaming built on published specifications. Those later documents are cited on the HTTP Live Streaming page in this corpus, and the difference in what can be cited is itself informative.