Messinger MIS 4477 Wide Area Networks

MIS 4477
Network and Security Infrastructure
JAKE MESSINGER (jake@uh.edu)

Wide Area Networks

My Teaching Notes:

The primary goal is to have students understand the major differences between the four general categories of services and to have some familiarity with the specific services offered. In many ways, dialed services and circuit switched services are the same. Likewise, the data rates for many services are similar so most of the internal network "plumbing" uses 64 Kbps PCM circuits and this is why the data rates are similar. The primary differences are the connection features (dedicated, circuit switched, packet switched) and the way in which the services are marketed to the users.

Dedicated circuit services have remained mostly stable of the past few years, with the exception of ever increasing data rates. This chapter needs further updating. The author still thinks ISDN is popular. In this country it is NOT. DSL killed ISDN. Why did DSL get so popular so quickly? RBOCs rapidly deployed aDSL., See ISDN: We Hardly Knew You. The book talks a lot about DSL but Cable Modem Service AND Wireless WAN (4G and WiMax) networking has really cut into the DSL footprint. Recent surveys of my class show that 95% of students have Cable Modem Service.

Circuit switched technologies (i.e., ISDN) is nearly dead with the exception of POTS dial up and ISDN PRI circuits. So you need to be able to know the difference between BRI and PRI. See the Primary Rate Interface Wiki.

SMDS is a new protocol replacing packet switched networks and ATM.
http://en.wikipedia.org/wiki/SMDS
http://searchnetworking.techtarget.com/definition/SMDS

Fitzgerald and Dennis
Chapter 9: Wide Area Networks

End of Lecture: Wide Area Networks