Networking Concepts

Computer networks by Andrew Tanenbaum 

Thoroughly updated, this classic bestseller, now in its fourth edition, reflects the newest and most important networking technologies with a special emphasis on wireless networking. The material on wireless networks includes detailed coverage of 802.11, wireless local loops, 2G and 3G cellular networks, BluetoothTM, WAP, i-mode, and others. It prepares students to work with wireless technologies in networks of all sizes-both local and wide area networks. There is also lots of new material on applications, including the Web, Internet radio, voice over IP, and video on demand. Finally, an entirely new chapter is devoted exclusively to security to help students deal with one of the most crucial topics in networking today

Computer Networking: A Top-Down Approach by Kurose
An emphasis on application-layer paradigms and application programming interfaces, encourages a lively, hands-on experience with protocols and networking concepts. KEY TOPICS: Computer Networks and the Internet; Application Layer; Transport Layer; Network Layer; Link Layer and LANs; Wireless and Mobile Networks; Multimedia Networking; Security in Computer Networks; Network Management; New discussions of VPN, IPsec, VLAN and updated technology treatment. MARKET: A useful reference for computer networking professionals.

Internetworking with TCP/IP, Vol 1 by Douglas E Comer
Are you looking for a good intro about TCP-IP Standards? This is surely the best. This book isn't about TCP-IP programming or implementation; I would say that it is an organized, gentle and concise presentation of the Internet documentation known as RFC ( request for comments ). After reading this book you should try "TCP-IP Illustrated, Vol. 1" by Richard Stevens, because it offers a more practical approach describing a real TCP-IP Internet "on the fly". After these two books you have a good background to read the Internet RFCs and more specific books about routing, firewalls, proxys, Internet high-level protocols and applications ( http, ftp, telnet, smtp, pop, etc ... ).