PDF of this tutorialNortel believes that ATM is the only viable backbone networking technology that can meet the objective of making multimedia calls as easy, reliable, and secure as voice calls are today.
ATM, coupled with SONET/SDH for fiber transport, sits at the core of Nortel's long-term architectural vision. That vision embraces various residential, business, and mobile access arrangements with a set of voice/data/video and, ultimately, multimedia servers. There will be many ways of accessing ATM networks including desktop ATM, switched Ethernet, wireless, and xDSL, to name a few. The vision includes extensive support of multiple classes of service for native ATM, IP–based, frame-relay-based, and circuit-based applications. ATM accommodates the inherently bursty nature of data, voice, and video applications and the compressibility of these traffic types for increased storage and bandwidth effectiveness. Nortel also believes that frame relay and ATM, being both virtual-circuit based, provide a service continuum supporting the broadest sets of speeds from sub-64 kbps all the way to Gbps. Finally, Nortel envisages a family of application servers around the periphery of this network to provide a range of data, image, video and voice services that take advantage of increasing insensitivity of the network to distance (see Figure 9).
Figure 9. Nortel's ATM Architectural Vision
