Page 254 - Optical Switching And Networking Handbook

11_200023_CH10/Bates 1/17/01 9:06 AM Page 239

The Future of Optical Networking (Where Is It All Heading?) 239

Figure 10-1 ?
Building block Futures
approach used

The Market

Application

Optical Switching

WDM DWDM

SONET SDH

Different types of fiber

Why fiber was invented

Changes in Infrastructure

In 1993, the Internet was a telecommunications network that ran on
a T-3 backbone and supported on-ramps (access) at T-1 speeds. For
the smaller organization, the access was on a 56-Kbps digital data-
phone service (DDS). From a networking perspective, the net looked
like a centrally controlled core of communications infrastructure
with smaller feeds leading into larger ones. As the number of end-
users grew exponentially, so did the traffic demands. The more end
points we added to the net, the greater the demand on the backbone
to support more data and more dense graphics. Figure 10-2 is a rep-
resentation of the users’ speeds.