As opposed to E1 links in Europe. Same same until you want to patch a US T1 to a European E1. Some sweet hardware money was made dealing with that. ( different framing, 2mbit/s instead of 1.44, 56kbps splits vs 64kbps splits. Clocks are a nightmare.

Story is that Bell tested the T1 in comms pits around Murray Hill NJ and when it worked for a long city block between two manholes they knew they had a product they could sell.

Watched a telco guy fix a broke E1 by sending one of the pairs a bit further round the krone frame to separate the signals better. I've even seen them add more wire to try and dampen down some local noise or reflectance or harmonics or something.

The old E1/T1 lines were sometimes pressurised and came with fancy brass taps to let the water out with its own teeny weeny bucket hanging off the tap. I kid you not.

Ha! As I remember, each end had an independent clock and a little bit of buffer to smooth out any variance. And it mostly worked!

The word "plesiochronous" is burned into my brain as a result of the few times that it didn't, though...

My career began in the late 90s telecoms boom, which was a gloriously chaotic period in retrospect. It seemed so very obvious at the time that "ethernet for everything" was what we should be working towards, but the legacy telcos didn't arrive at the same conclusion until well after the crash - so there were lots of opportunities for smaller players to undercut them.

Anything that isn't fiber is still frequently nitrogen pressurized.

Side note: as a teen I always wondered why those tanks never got stolen. When I got a car I stopped one day and checked- they were stamped with the teleco name. Writing this I wonder: did they stamp the regulator too?

Thanks for the bit of history. I read that by the early 1970s, a number of smaller recording studios in Los Angeles were linked by T1 lines to Capitol Records in order to make use of their famous reverberation chambers. I wondered who manufactured such high-performance ADCs and DACs at that time.

> Some sweet hardware money was made dealing with that

I used to work in a company that made good money on those