I found this book useful as my introduction to IP network communications (network layer). My background is not in networks but I was able to pick up this book and learn about; Routers, IP addresses and their assignments, Tunneling, Encapsulation, TCP/IP, Security issues, and Mobile IP to the extent that I understand the steps involved when a Mobile IP node moves from one link to another.
I have read many technical books/papers and most most of them clutter and disjoint ideas. Not this book. This book is methodical, orderly, clear and written in plain English. I think you will like it.
As an additional bonus, the book spends some time (10 pages) with an overview of TCP and explains why TCP works better over land lines than wireless media. There is a discussion of the problems processing real-time data over IP and proposes solutions.
I am an average reader and it took me approximately 30 hours to read the 300 pages over a period of five weeks. The book leaves out detail but references the IETF papers for the interested reader. The book had NO word "misspells" nor sentence "misspeaks". (I always notice those things.) There are great diagram sketches for example discussions.
The author was the Internet Engineering Task Force (IETF) co-chair of the Mobile IP working group and led the group to a deployable solution. The book explains that because he was involved since 1994 he understands the trade-offs and issues.