For your information Wiesemann & Theis makes various offprints available which we will be happy to send you. You can also download the contents of these offprints here as a PDF file.
TCP/IP Ethernet to the Web-IO
The seventh edition explains the basics of networkLeseprobe: PDF file
technology, all the key protocols from Ethernet to TCP/IP - but also newer technologies such as VPN.
Taking web standards to the terminal point
from "Ind. Ethernet Book"PDF: approx. 1 MB
(only in English)