An Introduction to Computer Networks
Computer Networks by Andrew Tannenbaum is also a great introductory text.<p><a href="http://cse.hcmut.edu.vn/~minhnguyen/NET/Computer%20Networks%20-%20A%20Tanenbaum%20-%205th%20edition.pdf" rel="nofollow">http://cse.hcmut.edu.vn/~minhnguyen/NET/Computer%20Networks%...</a>