دانلود کتاب Patterns in Network Architecture: A Return to Fundamentals

I was involved in the design of the ARPAnet Protocols and worked on Internet protocols. For about a year I was the chair of of the ISO Presentation Layer committee. I have a lot of first-hand experience with where we are today and how we got here.

I've just finished "Patterns in Network Architecture" and I'm impressed. While there are many things to argue over, the architecture Day describes sounds like it should work, and if it does work should be a vast improvement over the current ramshackle protocol structure. I haven't really done the hard work necessary to figure out if it really will work, and I don't expect to. And we know that the devil is always in the details. But I hope to hear sometime that an implementation has succeeded.

Like many others in the field, John has strong opinions and axes to grind. Rather than a shortcoming, however, I think his strong opinions and sarcastic wit are a benefit; any reader can see clearly where John is coming from and can research the "other side" if it seems important.

On page 79, Day writes:

"... two types of protocols tend to alternate in architectures. The MAC layer does relaying and multiplexing, the data link layer does "end-to-end" error control; the network layer relays, the transport layer does end-to-end error control; mail protocols relay, hmm no end-to-end error control and sometimes mail is lost. ...we can make two observations:

1. Relaying always creates the opportunity for PDUs to be lost. Therefore, to guarantee reliability, there must always be an error-control protocol on top of a relaying protocol.

2. This would seem to indicate that there are really only three fundamental types of protocols:

- Two data transfer protocols: Relaying and multiplexing protocols
and error- and flow-control protocols with different policies

- Application protocols"

The rest of the book goes on to develop these thoughts, which in my view is a real breakthrough in clarity.

This book ought to be used as a textbook! It is highly recommended to everyone working in the field. If only there weren't so many distracting editorial errors.