This is an excellent book, but the patterns (Connector, Acceptor, Acceptor-Connector, Reactor, Proactor, Half Sync-Half Async .....) are all available in MORE expansive (yes more expansive) form on the ACE site.

Just Google "ACE Framework" and you will see Doug Schmidt and his ACE related papers section which will conveniently list all the patterns in this book plus a ton more (yes more useful patterns NOT in this book). The related papers are ALL in PDF format and can be loaded into a PDF reader (see Altrix Illiad E-Book reader) or printed out to a bind. The sites PDF editions are extensively longer and more detailed than the book editions, so you are better off going to the site instead.

These is indeed an excellent reference, but considering that most of the patterns are now implemented in ACE (see ACE Programmers Guide) or even in Java (see Java 1.5 SE and up in the java.util.concurrent for concurrency).

The books C++ Network Programming Vol 1 and Vol 2 are much better and re-visit these patterns from which you can, again, get on the site for free and in a nice color illustrated edition (PDF).

Save your $70 and visit the ACE site.