[bwann]

To nitpick, the 53.3k limit only affected US Robotics' pre-V.90 standard called X2, due to how much power they would require, which violated FCC rules. K56Flex (the competing 56k protocol), and later the ratified V.90 standard didn't have this problem and you could achieve carrier speeds of 56,000 bps.

This distinction was getting lost to time even back then with everyone just assuming it was some arbitrary FCC limit. This post from NANOG in 1998 explains it: https://archive.nanog.org/mailinglist/mailarchives/old_archi...

[qingcharles]

What's crazy is how badly I was waiting to upgrade from X2 to K56Flex just to get the 3kbps, which was like a life-altering speed difference back then!

[guidedlight]

3.2kbps is the maximum rate of symbols (i.e. 3200 baud). So K56Flex squeezes one extra bit per symbol.

[philistine]

I’ll go to my grave thinking wow 3.2 kilobytes is a good connection!

[rascul]

I don't know how it worked but I never saw better than 53/54k with v.90 or v.92. Maybe there was more going on.

[MBCook]

Once, for a short while, I was getting around 110kbps reported from my modem (obviously it was doing compression).

It couldn’t do it for binary, but it still was noticeable with HTML and email.

It didn’t last long. Whatever accidental phone line + ISP magic enabled it was quickly “fixed”.

[Aloha]

It really depended a lot of how clean your pair was, and sometimes even what kind of switch you were homed on.

Like channel banks prior to the D4 and a 1AESS would very likely have a marked difference to your speeds.

[tibbydudeza]

Ahh the 56K modem wars - each group swore either by USR or K56Flex and were incompatible with each other until V90 standard came along - some modems could be firmware upgraded (USR) others not that used discrete components.

[hypercube33]

I'm pretty sure my external modem had a firmware update that took it from 53kbps to 56k flex