eering 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. First Things First First Things First Figure 1-8 The parallel bus ribbon cable in a PC Ribbon Cable (Parallel Bus) Figure 1-9 The parallel bus, this time etched (inside the circle) on the mother- board of the Finally, we offer simplex, half-duplex, and full-duplex transmission. Simplex transmission means "one-way only," like a radio broadcast. Half- duplex transmission means "two-way, but only one way at a time," like 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. First Things First Chapter 1 CB radio. Finally, full-duplex means "two-way simultaneous transmis- sion," like telephony or two-way data transmission. Network Transport The fabric of the network cloud is a rich and unbelievably complex col- lection of hardware and software that moves customer traffic from an ingress point to an egress point, essentially anywhere in the world. It's a function that we take entirely for granted because it is so ingrained in day-to-day life. But stop for a moment to think about what the network actually does. Not only does it deliver voice and data traffic between end points, but it does so easily and seamlessly, with various levels of service quality, as required, to any point on the globe (and in fact beyond!) in a matter of seconds-and with zero human involvement. It is the largest fully automated machine on the planet and represents one of the great- est technological accomplishments of all time. Think about that: I can pick up a handset here in Vermont, dial a handful of numbers, and sec- onds later a telephone rings in Ouagadougou, Burkina Faso, in North Central Africa. How that happens borders on the miraculous. We will explore it in considerably greater 