The 56k Modem: How It Broke the Shannon Limit

In the dial-up era, 33.6 kbps was once considered the speed limit for modems on standard phone lines. However, the 56k modem emerged, shattering this limitation. This wasn't a breakthrough of Shannon's Law, but a clever exploitation of the digital transformation of the phone network. At the time, the core of the phone network was digital, only the 'last mile' remained analog. The 56k modem achieved higher speeds by having ISPs send digital signals directly into the phone network, bypassing analog conversions. Although actual speeds were affected by line quality and other factors, the 56k modem made the internet noticeably more usable before broadband became widespread.