I visited the bookstore (you know, those places you bought books before Amazon.com) and picked up a copy of "Trust in cyberspace." Although much of the book is concerned with "security," I was pleased to see some coverage of other problems which reduce people's confidence in network systems. The chapter on the "Public Telephone Network" (PTN) and the Internet trustworthiness has a very good overview of the design decisions, types of failures and attacks. Unlike many cyber-assurance studies which only focus on the "hacker" attack; congestion, link failure (aka Backhoe attack), and operator error are included in this book. Most of us are aware of the security weakness with the current Internet, but this book is one of the first I've seen to list several weaknesses in the Public Telephone Network in on place. One oversight is the book doesn't really explain the definition of "failure" or "outage" varies between the PTN and the Internet. So you can't easily compare reliability measurements between them. The famous 99.999% reliability of the PTN doesn't translate to the Internet because the Internet measurements include things normally excluded by the PTN measurements, e.g. congestion. One important buzzword I would call your attention to is "Minimum Essential Information Infrastructure." This is a creation of a RAND researcher in 1995, and is percolating around the cyber-assurance groups.