[aidenn0]

In the 90s in my little corner of the mid Atlantic US at least, it was very commonly called a T1 or DS1 and the terms were used interchangeably even though they refer to slightly different things (at least by sysadmins; use the terms wrong around a telecom equipment engineer and you'd likely get corrected).

[jsjohnst]

I'm aware the misnaming was common, but it's a bad idea to do so. There's a pretty big difference between a T1 and a PRI in practice when used as a data only circuit. For one, the T-1 is a fair bit faster.