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T1: A Survival Guide
What a great age we live in, where you can teach YOURSELF your entire profession! As a self-taught network engineer with a major market data firm, I have great respect for some of today's tech writers who have single handedly taught me TCP/IP, Ethernet, Cisco routers, and Linux! The only aspect of my job for which I have had to rely solely on experience, (and the meager amount of information on the web) is T1s and synchronous circuits/leased lines. As far as I know, the only books which discussed the technical details of T1 and synchronous circuits are general telecommuncations text books. None are written from a contemporary network administrator's point of view. So, you understand my excitement at seeing O'Reilly take a stab at just such a book!
The book starts off at a good pace, talking about the history of the telephone network and its evolution into the digital age (the reason we have T1 available as a data service). It discusses the different terminology related to T1's, and the equipment that connects them to our routers, but makes very few analogies or examples to solidify the relationship of these terms to each other or to the big picture of networking. After discussing the physical and logical layout of T1 and its physical interface with our routers, Gast spends the next 40 pages on the nitty gritty details of T1: Timing, Framing, Coding, and the lights on the CSU/DSU. All the important aspects of T1 are discussed in a logical order. Unfortunately, it's not enough; Gast breezes through the most important and mysterious aspects of T1 without so much as one good analogy or explanation to develop the ideas. The diagrams are equally disappointing. They have a lot of information, but do little to clarify the subject matter. The T1 framing sections, especially did not get enough attention. This is the heart of T1, and really wasn't explained well enough.
After getting what seemed to be an introduction to the subject matter, I expected the rest of the book to go into further detail about the intricacies of T1 framing and coding, and ways to hash out possible problems on T1 circuits. Instead, the next 60 pages give the boring and useless details of the three most common link-layer protocols run over T1s: HDLC, PPP, and Frame Relay. Gast continues to litter the pages with confusing and uninformative diagrams, and then spends time explaining the details of each one step-by-step. Good diagrams don't need step-by-step explanation; they speak for themselves!
The level of detail he goes into for each of these protocols is similar to what you might find in a general Data Networking text. He discusses different principles of data communication as well as the specific frame formats of these protocols, but doesn't explain how these protocols specifically interact with T1. Although he gives the frame formats of these different WAN protocols, he doesn't give enough information or suggestions on using the information in any effective way. The oversimplification of many of the diagrams makes the book less useful than the RFCs which will give you the exact frame formats.
Gast assumes that if you don't work for one of the telcos, the only way you may come across a T1 is as a small business network administrator responsible for maintaining internet access via T1. That is not the case anymore; many large companies manage their own backbone and have access to leased lines, and T1 testers. The only time a T1 tester is mentioned, it's described as 'a handheld device with lots of buttons and blinking lights on it.' The principles behind T1 testing are quickly covered, but the intricacies of testing T1s and using T1 testers are not. This is unfortunate, as many Cisco routers have built in test pattern generation and loopback capabilities! (As do most standalone CSU/DSUs.)
It's obvious, as it is in many poorly written tech books, that the author knows his subject! The problem is, he doesn't consider the fact that we, the reader, may not. The book wasn't a complete waste of time; there is a lot of good information in here. Information on signaling and different types of alarms on T1s is present. The majority of it is just not explained very well, and too much time is spent on the link-layer protocols. I probably wouldn't be so down on this book if it didn't have O'Reilly's name on it.
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Cisco Connection Online is the bomb.
Granted you have to dig quite a bit to find what you need, but it is all there. Everything you wanted to know, diagrams, how stuff connects to other devices, etc., all can be found there. I am not a Cisco employee, but I hit that site everyday during the course of my job.
Just curious, if you read this post, what exactly were you looking for? Specifics, not in general, maybe we can help you find what you are looking for.
Sent from your iPad.
I sure am excited to read this review! You can tell because I use so many exclamation marks in my first paragraph!
I'm having flashbacks of Tiny Elvis for some reason. "Woah! Look at the size of that icon! That thing is huuuge!!"
Yes, I understand your excitement. Those first three exclamation marks really drove it home.
DataSquid.net, a little about me.
It was a "Survival Guide", not an in-depth treatise on the mysteries of a T1 line for anal-retentive system administrators. In my opinion, if you have to diagnose andrepair your own T1 line - your company sucks and you should find a new job or you're in the wrong line of work.
It's a well known fact that people who know a lot about a subject, and may be able to answer any question you may have if you ask them, simply can't write a book or teach a class to save their lives. Extensive knowledge does not always lead to ability to teach. I'm sure the book is extremely informative for someone who would like a reference to things related to T1, but for someone who wants to actually learn it (Such as myself), this would probably be a very difficult read at best.
I think I concur with the author in that, if it wasn't an O'reilly title, which has a history of good explanations and good writing, then it wouldn't be such a problem.
Randal Graves says: I'm a firm believer in the philosophy of a ruling class... Especially since I rule.
Sometimes firsthand knowledge from other living people can never be replaced by a book. If you're looking for more then an overview of the technology and want a specific problem solver try mailing lists, or talking to people in the profession. This book isn't a troubleshooting guide.
ahh, the egg in the basket..
Second Ed., George Sackett, from McGraw Hill technical. Or you could just get an EE degree... and then read the handbook, and telecommunications manuals explaining what all this bits do...
Well it is a real disturbing tendency to pick up the book coz of a big name. and the publishers know of this. Go to their website and check out some new books. most of them are nothing compared to what we used to get a couple of years ago. The big publishers are gettin compalacent or what. Coming out with a book for the heck of it! Another thing i have noticed in all O'reilly books, infact in all big names, that the first chapter is the same. History, then a little bit of introduction and finally all of a sudden you are in a maze! I Dunno what happened to the Days of the Perl CookBook!
My Aurora : http://www.youtube.com/watch?v=o91ZsGwJYyg
FB : https://www.facebook.com/TanveersPhotography
Since time immemorial, the principle of being self taught has been prevalent throughout society. Especially in the arts, but also in Sciences, where people read books and all that and became famous without any professional qualification.
The difference with Internet, is that you can learn about it by using it, from anywhere, at the same time as everyone else, and it truly is becoming a universal skill.
But in all, apart from overuse of the exclamation mark, a reasonable review.
Conversion Rate Optimisation French / English consultant
Pretty much my assessment as well. With no practical line-level debugging information, I came away with little more than a gift-book for the half-priced book stores.
;)
Some practical information about using a "T-bird" device would have been helpful -- even more helpful would have been something that would suggest a "build your own t-bird tester from spare vacuum cleaner parts and save a bundle"
Whenever we've had serious problems -- rolls, flips, and bad CSU-DSU cards in the demarc, its either through trial and error "lets see is this really the TX pair? and is it polarity right?" -- or we beg, threaten, bully the CLEC test-and-turn up crew to send out a lineman, who invariably shows up with a t-bird box and pin points where the issue is.
Something also seriously lacking is some other non-protocol uses for T1 splitting, such as slicing Channelized T1 for voice, data.
All in all, save your O'reilly bucks for something you really need
Old age and treachery almost always overcome youth and skill.
because all the things you disliked makes me want to buy this book actually! Looks like inerresting geek food. I don't know nothin about T1s but I guess that if I want to configure / test / manage them I'll have read the Manuals that come with the routers / switches / testers / whatever anyway??
delete free(system.gc);
There are several points that the reviewer brought up, but never expanded upon. I'm curious to know what exactly he thinks are "the most important and mysterious aspects of T1"? Also, I don't understand his problem with the WAN protocols. He states that the section is boring and useless, then says that it is important. I'm not sure how WAN protocols pertain to T-1 at all. T-1 is lower on the ISO model that WAN protocols anyway.
I spent the majority of my day yesterday babysitting a T-BERT. We're having a mysterious problem with a voice T1 that has channels drop off occasionally. All the vendors are pointing fingers at each other.
Anyone happen to know any other good resources for troubleshooting T1's? The Cisco link above looks interesting.
----- obSig
I believe Sarah Connor survived the first Terminator by crushing him with a trash compactor back in T1.
Oh, you mean *that* T1.
It's immense, it is not intended to be the "gimme a quick answer right away because I have no patience" type of website. It is much like an engineering college's research library and as such, it needs to be studied thoroughly, and learned how to be used before using it. Once you've mastered the usage of CCO, you will then have achieved a well-founded education in Cisco's world of datacomm technology.
...because it doesn't have improper use of apostrophes, such as "the meager amount of information on the web is T1's and synchronous circuits/leased lines". Before posting again, please read Bob's Quick Guide to the Apostrophe, You Idiots.
Check out our infosecurity industry blog: http://securitymusings.com/
I'd much rather have a giude how you'd survive if you were on place in T2 (roflmao @ joke). That's "Terminater 2" if you don't get it LOL ;)
The reason so little time is spent on the details of T1 framing and coding is because it's really simple. T1 is hard for many people to understand because they try and make it hard. Coding is really simple. Framing is simple as well. It never changes. Moreimportantly, the guy on the other end of the line troubleshooting the circuit probably won't know how to fix it. Once you know what RED, YELLOW/AIS/BLUE alarms are and what they really mean is going on you can solve T1 problems very quickly.
As for test equipment, what test equipment do you want information for? There are several test boxes just in the T-bird family, and each one has a different setup. It would make the book rediculously large to cover them all, and then people would bitch because it didn't cover digital lightwave test equipment, etc.
Maybe you should e-mail the author and let him know what you thought about the book- who knows, maybe it will inspire him to do a second edition that will address your concerns.
slashdot!=valid HTML
I had all kinds of trouble googling for info on a "T-bird tester" until I figured out it was actually a T-Berd...
. We've got computers, we're tapping phone lines, you know that ain't allowed - Talking Heads, "Life During Wartime"
http://www.cisco.com/warp/public/116/t1_flchrt_mai n.html
Flowcharts, etc. T1s are hard if you make them hard. Or if you use Bay routers :)
Don't Panic...
That being said, I've met a lot of people who were good writers but terrible technical communicators. They do a good job of explaining technical concepts, processes, and so on. But when it comes to all the boring little practical details, they just don't have the patience.
There's also issues of ego. Everybody has their own notions of what "everybody knows" or what's the "simplest" explanation. And of course everybody is wrong about these things some of the time. The best writers in the world can screw up in this way. So they need a skilled editor to help them see this issue.
O'Reilly seems to have a particular problem this way. They cover a lot of technologies with a limited audience -- such as T1 -- and they contract leading technical people to do it. Often the very inventors of the technology. It takes a really good technical editor to tell somebody like that, "That's a little unclear" or "You need to organize the material better," without bruising any egos. Not a lot editors that good -- and I don't think any of them work at O'Reilly.
It's a survival guide, not necessarily a flurish guide :) If you're not dead it was a success.
The most important thing to know about T1's is that
the technology has been around since the 1960's and
that Telco personnel STILL don't know how it works.
It can still take a traditional telco six months to
install a line, and more than a year to get it working correctly.
For testing, I recommend having/using a T-Berd and
a Sage. The T-berd is what the Telco techs use, so
you can test with them, end-to-end, using compatible devices.
They won't acknowledge the validity of any any other device, and blame "your equipment".
The Sage will give you more information about obscure timing glitches, gather stats, and has a wide variety of tests. Running a test with a high
concentration of zeros will show noise glitches
on the line; running lots of ones will stress the repeaters and power supplies. Make sure your test
pattern does not violate the framing rules for your
circuit-you can't run all zeroes on a non-B8ZS circuit, it looks like a dead line!
Make sure you have a jack panel at the circuit end so you have a way of inserting and dropping out of
the circuit. Wire the jack panel so you can plug in
"looking in" both directions. Have a "copper loop" for testing; when the Telco blames your equipment, tell them you HAVE NO equipment, just a T-berd on one end, and a copper loop on the other, so the problem is THEIRS to fix.
I have a very good, proprietary, in-house textbook on T-1s which was originally published internally by New England Telephone (now Verizon). The lady that wrote it was excellent--she was so good at her job, they did the only reasonable thing they could--they FIRED her. I don't know how you can
get a copy, mine is STOLEN--but it has six chapters, labelled "T1 Fundamentals", "Station Equipment", "CO equipment", "Circuit Testing", "ANSI testing", and "Tech Talks". No front cover or publication#. Mine is not for sale.
If you call the Telco for service, and get a knowledgable tech (this is RARE), get him coffee and donuts and pump him for information. It may be
the only way to learn what you need. Be aware that Telco personnel use their own internal jargon
that bears no relationship to anything else in electronics--you will need to listen carefully, then translate the "telco--ese" into english.
Good luck with your T1's, and keep praying for a
better source of broadband than the phone company.
After all, they are the ones who have been PREVENTING communication for over 100 years....
As far as I know, the only books which discussed the technical details of T1 and synchronous circuits are general telecommuncations text books.
There's a good bit of info on T1 lines in some of the professional level cisco cert study guides... also, here's an interesting paper on everything you wanted to know about T1, but were afraid to ask.
It's easy to pick up many books published within the last ten years and learn about ESF B8ZS, etc. What we REALLY need is a book on how to get what you want from the telco, how their resellers work, the horror stories that have happened, etc.
A friend of mine is getting a DSX "presentation" over DSL, and it was sold to him as a T1. This is out and out fraud, but he doesn't know what to do about it.
I know rules and regs and tarriffs vary from state to state, but a book written by a few people could expose the gotchas that have bittin me in the ass in dealing with T1/PRI.
Good, informative links for those new to T1 s.
How to order a T1 - the BrandX way. And costs $$
http://www.brandx.net/help/ordering-a-T1.html
http://www.intel.com/support/express/routers/
( above looks boring, until any router-entry is clicked. )
Sangoma cards [sangoma.com] - Linux
and: http://www.sangoma.com/products.htm
- about $900 for a PCI T1 DSU/CSU.