August 2001
Beginner
304 pages
10h 3m
English
Content preview from T1: A Survival GuideBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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Chapter 6. Mysteries of theCSU/DSU
A man is as old as his arteries.
—Pierre J. G. Cabanis,Epigrams
When bringing up a T1, a CSU/DSU is required by FCC part 68 to protect the telco network from your equipment. If the CSU/DSU does not function correctly, whether due to component failure or misconfiguration, the line will not come up. Unfortunately, producing clear, understandable printed documentation has never been a goal of data communications equipment vendors. CSU/DSU manuals have improved to the point of basic intelligibility, but even the best manuals require a solid understanding of telco networking.
Line Build Out: Moving BetweenTheory and Practice
In a perfect theoretical world, wires have no resistance and voltage pulses can travel forever. The real world, however, is rarely anything like the world of theory. (There is a reason that physicists joke about spherical frictionless cows, after all.) Repeaters and signal regenerators along T1 spans are the first admission of a practical world. Line build out (LBO) is the second concession to practicality.
Two different types of connections are used on T1 lines. A long-haul connection is made to the telco network. The first repeater may be up to 3,000 feet away from the end-user location. CSUs must be able to drive the pulse up to 3,000 feet, so the arriving pulse at the first repeater is still strong enough to be regenerated. Long-haul line build out is used to avoid problems that arise from having multiple T1 customers in an ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.