city switches or Figure 7-25 MEMS mirror (Photo courtesy Lucent Technologies) Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Transport Technologies Transport Technologies cross-connect devices. They are not routers, because they do not perform layer three functions. They will, however; now that the "nuclear winter" of the telecom industry has ended, all major manufacturers have announced plans to incorporate a layer three routing function into what will become their devices. Optical networking, then, is a major component of the modern trans- port network. Together with switching technologies like frame relay and ATM, and physical layer standards like SONET, SDH, and copper-based transport technologies, the current network is able to handle the trans- port requirements of any traffic type while overlaying quality of service at the same time. An Aside: A Trip to the Wave Venture While working in Singapore recently, a friend approached me and said, "I just finished reading your Optical Networking Crash Course book. And I noticed that you didn't have much to say in it about submarine cables." "Yes," I replied, explaining that the book was really designed to explain the nature of terrestrial systems. I also added the observation that I had no experience in the submarine domain and didn't feel equipped to tackle that subject in detail in the book. "So you've never seen a cable laying ship?" he asked. No, I replied. "Would you like to?" He countered. "Absolutely!" I said, probably a little more enthusiastically than I should have. He explained that a good friend of his was the President of Asia Global Crossing, that they had a ship in port, and if I wanted he could probably set up a tour. So, he went away to make a phone call, and when he returned he told me that it was all set we would tour the ship on Friday. Friday morning arrived, and we took 