Dave Tweed wrote: >Nate Duehr wrote: > > >>Ain't all this stuff FUN? ;-) >> >>Telco geek for many years turned Unix geek, but still love telco as >>it's such a cool "natural" progression of technology for 30 years... >> >> > >Yes, it is. While the general concepts of your narrative were mostly >accurate, the details were wrong in almost every respect. I'm speaking >as a recent (up until 2002) designer of T1/E1 terminal multiplexer >equipment. > >For example, repeaters were never "powered by the signal". The >ones density requirement is related entirely to maintaining clock >synchronization. AMI doesn't help create ones density, but bit-8 >stuffing and B8ZS do. > > Well, I had a mentor who claimed to have "been there and seen it", I'm not old enough to remember the 60's. He had rather true-sounding stories of having to jump start such devices with batteries, after some span failures. His recollection of this stuff is clear back to early Bell Labs tests of these types of circuits, but I can't verify his accounts personally in any way. I do understand your point also, and it's been a long long time since I had to deal with T1's on a daily basis, so memory is a bit fuzzy. >And so on. I don't have time to address all of your points. > > Well here's hoping it at least gives a "feel" for the general evolution of the technology. I certainly had hoped it was more accurate than I guess it was from old grey-matter, and I'm operating on about 8 hours of sleep in 72 hours total right now, so maybe during a more awake state I'd have explained things better. Generally the intent was to remind folks that there's a *whole lot* more going on when dealing with modems and analog lines between the wall jack and the CO than meets the eye in most modern neighborhoods. I really would be interested in seeing how your more practiced professional descriptions would go from my rambling rant of a (I guess, bad...) history lesson. If nothing else for posterity's sake so the PICList archives have "the Right Stuff" in them. ;-) Oh well... back to banging head on keyboard wondering why HP-UX has to do things differently than most Unix's just to confuse the sysadmin... Nate Duehr, nate@natetech.com p.s. I hope I've figured out how to turn off HTML mail in the new Mozilla Thunderbird I'm playing with here... the developers in their infinite wisdom also appear to have moved all of the usual controls for that from places they've been since Netscape 4.x ... user-hostile interface design, indeed! -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu