Customer Reviews

ASN.1 Complete

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4 star:		(2)
3 star:		(1)
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This book does an excellent job of not only explaining how ASN.1 works but why it works that way. It is obvious that the author is an expert in this field. His explanations are clear and he makes good use of diagrams. He also draws on historical evidence and his own experiences.

The author has a literary style that makes what could be a dry and boring subject easy to read, and in some places quite entertaining.

This book is excellent ASN.1 reference material as well as a strong instructional work dealing with ASN.1. 'ASN.1 Complete' was apparently aimed for a multilevel audience: People who have no prior experience with ASN.1, those who are learning ASN.1, and those who merely require satisfactory reference material on ASN.1. For all intents and purposes the author successfully geared the discussions toward any person who deals with ASN.1 on any basis, as they would evolve in their usage of ASN.1. Larmouth does not discuss the material in a monotonous manner as do so many other authors, however he is able to teach with 'programmer's sarcasm and humor', without deviating from the purpose he is teaching. A rather difficult task at times. The only major weakness of 'ASN.1 Complete' is, inevitably, the inability to provide the 'absolute beginner' with the information required to apprehend the information upon it's introduction. The non-familiar reader would be best off reading Section 1 straight through and then going back to re-read all of the sections from the beginning.

Section 1: Section 1 introduces ASN.1, describes it's intents and history. Larmouth gives the reader an overview of the ways ASN.1 can be used and how it is implemented (the theory behind implementation). Most of the basic features are introduced, not discussed in great detail.

Section 2: The basic areas of ASN.1 are discussed thoroughly, and many intermediate topics are introduced and explained. Larmouth usually gives examples supporting the current discussion. Toward the end of the section Larmouth dedicates chapters to the more advanced areas, giving a better understanding to the reader.

Section 3: Mostly for implementors and programmers, Section 3 ventures deep into the sets of encoding rules. Larmouth focuses on the 2 most common sets of encoding rules BER and PER. It would seem that the author favors PER, however the discussions are very relevant and explain many things that an implementor must know.

For the person that is beginning to learn ANS.1 this is an excellent selection; it will teach ASN.1 to the reader and give a much needed overall understanding to ASN.1 very quickly. It is obvious that the author has done his homework. Anyone at any stage of ASN.1 usage would find this as an excellent addition to a reference library; finding specific topics with ease is not a problem. Tip: sometimes the notes on the sides of the page contain humor, but most of the time, the information is very useful. Keep in mind also that this book was not necessarily written to be read straight through, ironically it is only necessary to read the sections and chapters that apply to the information that is needed.

I read this book cover to cover back when I had to deal directly with parsing ASN.1. The book is an interesting read, excellently and expertly written. Moreover, I felt like an expert when I finished reading it; I took my new-found knowledge and applied it to my work at hand. Of course, there are portions of the book that are more theoretical than practical, and I didn't have the tools available to build ASN.1 parsers from rules. However, ASN.1 is important despite the dearth of information on it. This book doesn't merely fill the void - it makes a dry topic interesting.

This is a difficult book. Difficult to read and difficult to review. But I can't say it's a bad one.
After reading the first chapter I thought: "one of the best 7-layer OSI model explanation I've ever read"; then I read the rest of the book and I thought: "ehm... what?..."
I had to re-read it completely another time, going foreward and backward to follow the concepts, and integrating it with documents found here and there on the web, in order to have a good idea on the arguments.
After the first time reading, I did not even understand that "information object classes" have nothing to do with "object identifiers" (because they have nothing to do each other, isn't it?...)
Maybe this is the result of the fact that the author is an international standard writer!... ;-)
If you ever had the chance to read an ISO/OSI/UNI/EN/etc. standard specification, you understand what I mean: international standards are always a big mess.
Could be this the reason because ASN.1 is so little diffused: although it was born long time ago, ASN.1 power seems far bigger than its diffusion.
I am an embedded engineer developer, and I always have to deal with the problem of exchanging data and commands between (usually many) microcontrollers in the system: in other words, to specify and implement custom protocols.
ASN.1 could be a big help when specifying protocols, also for small 8bit microcontrollers (I think that in this case the protocol encoder/decoder implementation should be hand-written); when using high-end microcontrollers (ARM7 or higher, for example) ASN.1 tools (compilers) like the open-source asn1c could be used (maybe with some customized optimization wrappers, in my opinion).

But this book is not oriented to the practical point of view; I think that a text like this should explain:
- what I can do with ASN.1
- how I can do it

I will take care on my own about thinking on "why I need to do it" and I'm not much interested in "why ASN.1 acts in this way", and in an long list of "excusatio non petita" on ASN.1 internals as this book is full of.

I'm not saying that "ASN.1 Complete" does not explain what you can do with ASN.1 and how: it does, but you have to search it hidden in a lot of other rether confusing material.

Unfortunately there are not many other ASN.1 documents/books available. Moreover, ASN.1 sample code is very difficult to find. As an example, the ROSE protocol is cited in this book, and a ROSE protocol subset could fit perfectly in many embedded fields, but there is NO WAY to have even a minimal implementation from this book, and I can't find any on the web.