Let’s face it: we’re spoiled as we speak; most of us get irritated if the 4K video we’re streaming must take a few seconds to buffer. However our fashionable web speeds would have been unthinkable within the days of dial-up, when 56kbps was the top. That does, nevertheless, make one marvel what speeds are doable with dial-up modem know-how. Are these speeds sufficient to stream a YouTube video? The oldsters over on The Serial Port channel determined to search out out by pushing dial-up modems to their limits.
Let’s kick issues off with a terminology lesson which will shock some readers: the “ok” within the time period “56k modem” refers back to the velocity in kilobits per second. So, a 56k modem can transmit as much as 56 thousand bits every second. Discover that I’m utilizing the phrase “bits” and never “bytes” right here, which is what we have a tendency to make use of to measure file measurement. That implies that web speeds, measured in bits per second, are eight instances slower than what many individuals anticipate.
All of that to say that 56k modems have been very sluggish. And, after all, there have been plenty of dial-up modems with even slower speeds than that. However there’s a trick that permit The Serial Port workforce enhance the state of affairs and that’s Multilink PPP (Level-to-Level Protocol).
Multilink PPP was a system for primarily combining a number of cellphone strains and dial-up modems to extend the entire bandwidth. That wasn’t frequent within the dial-up period, because it required a number of strains and an ISP that supported the know-how. However The Serial Port workforce was capable of actually flex Multilink PPP’s capabilities by primarily creating their very own ISP. They did that by utilizing a CISCO IAD, which is a voice-over-IP gateway, to generate analog cellphone strains for a number of 56k dial-up modems.
The CISCO IAD has T1 community connectivity, which can be very outdated at this level. However it helps 1.544 Mbps (megabits per second), which is sufficient for this check.
The Serial Port workforce then linked these cellphone strains to a number of 56k modems, going to an IBM ThinkCentre A50 operating Home windows XP. There was some bother with the serial connections and COM port assignments, however they have been capable of get Multilink PPP working.
First, they linked two 56k modems and have been capable of obtain precise speeds near 100kbps. Then they elevated the depend to 5 56k modems and broke 200kbps — sufficient to stream a YouTube video at 240p. Lastly, they reached a scalding fee of 668kbps by connecting 12 modems. That permit them play YouTube at an truly kinda watchable decision.
In concept, it might be doable to attain even quicker speeds, however that appears nearly crass at this level.