Chapter 7 – Wide Area Networks

As the title indicates this chapter is all about Wide Area Networks (WAN). In previous chapters we have learned that WAN’s are networks that connect two or more geographically distinct Local Area Networks (LAN). It covers the following WAN topologies:

• Bus- Wan connected to no more than two other sites in a serial fashion.
• Ring – Each site is connected to two other sites so it forms a ring.
• Star – Single site acts as the central connection point for several points.
• Mesh – All sites are connected to each other.
• Tiered – Sites are connected in star or ring formations are interconnected at different levels.

 It explains Public Switched Telephone Networks (PSTN) and how this media connects computers using telephone carrier equipment. The text covers the different types of service used to accomplish this such as ISDN (Integrated Service Digital Network), DSL (Digital Subscriber Line), and T-Carries.

It proceeds to talk about Broadband cable and its use of coaxial cable. It touches on broadband over powerline. It goes into Sonet (Synchronous Optical Network) which was developed by Bell Communications Research in the 80’s. Sonet specifies framing and multiplexing techniques at the physical layer of the OSI model. It follows up with much detail explaining how it works.

The chapter was loaded with diagrams, pictures and charts which helped in understanding the many concepts presented. I found the chapter very informative.