Anyone here remember when AT&T stood for reliability? Heck, the US government wouldn't buy critical communications circuits from anyone else back when I joined the military 19 years ago.
But, then again, back in the day, AT&T (or, expanded, Bell Tele) would not let folks buy anything other than from themselves. For a fun read, see the link below. It's a very short federal district court report, but it speaks volumes about the telecom industry prior to the breakup in the 80s and the 96 Telecom Act.
Sorry for the tangent...
And for a look at what a Hush-a-Phone is (what a high tech piece of... get real, it's plastic!), see: