YouTube… Over Dial UpIn the days of yore, computers would scream strange sounds as they spoke with each other over phone lines.

[cybersecurity@poliverso.org]

YouTube… Over Dial Up

In the days of yore, computers would scream strange sounds as they spoke with each other over phone lines. Of course, this is dial up, the predecessor to modern internet technology, offering laughable speeds compared to modern connections. But what if dial up had more to offer? Perhaps it could even stream a YouTube video. That’s what the folks over at The Serial Port set out to find out.

The key to YouTube over dial up is a little known part of the protocol added right around the time broadband was taking off called multilink PPP. This protocol allows for multiple modems connected to a PC in parallel for faster connections. With no theoretical limit in sight, and YouTube’s lowest quality requiring a mere 175 Kbps, the goal was clear: find if there is a limit to multilink PPP and watch YouTube over dialup in the process.

Setting Up the Server Side Connection

For the ISP setup, a Cisco IAD VoIP gateway with a T1 connection to a 3Com Total Control modem was configured for this setup. On the client side, an IBM Net Vista A21I with Windows ME was chosen for its period correct nature. First tests with two modems proved promising, but Windows ME dials only one modem at a time, making the connection process somewhat slow.

But for faster speeds, more ports are needed, so an Equinox com port adapter was added to the machine. However, drivers for Windows ME were unavailable, so a Windows 2000 computer was used instead. Unfortunately, this still was an unusable setup as no browser capable of running YouTube could be installed on Windows 2000. Therefore, the final client side computer was an IBM Think Center A50 from 2004 with Windows XP.

But a single Equinox card was still not enough, so a second eight port com card was installed. However, the com ports showed up in windows numbered three through ten on both cards with the driver unable to change the addresses on the second card. Therefore, a four port Digi card was used instead, giving a total of thirteen com ports including the one on the motherboard.

Testing with a mere four modems showed that Windows XP had far better multilink support, with all the modems creating a cacophony of sound dialing simultaneously. Unfortunately, this test with four modems failed due to numerous issues ranging from dial tones to hardware failures. As it turned out the DIP switches on the bottom of the modems needed to be set identically. After a few reterminating cables, three of the four modems worked.

The next set was eight modems. Despite persistent connection issues, five modems got connected in this next test with just over 200 kbps, 2000 era broadband speeds. But a neat feature of multilink is the ability to selectively re-dial, so by re-trying the connection of the three unconnected modems, all eight could work in parallel, reaching over 300 kbps.

But still, this is not enough. So after adding more phone lines and scrounging up some more modems, an additional four modems got added to the computer. With twelve modems connected, a whopping 668.8 kbps was achieved over dial up, well in excess of what’s needed for YouTube video playback, and even beating out broadband of the era. Despite this logical extreme, there is still no theoretical limit in site, so make sure to stay tuned for the next dial up speed record attempt!

If you too enjoy the sounds of computers screaming for their internet connection, make sure to check out this dialup over Discord hack next!

youtube.com/embed/LZ259Jx8MQY?…

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hackaday.com/2025/09/29/youtub…