1. 1 Broadband Integrated Services Digital Network (B-ISDN) Carey Williamson University of Calgary

2. 2 Introduction n B-ISDN is an all-purpose digital network that will support a wide variety of applications and services in a flexible and cost-effective manner n Successor to Narrowband ISDN (called N-ISDN or ISDN) n B-ISDN assumes transmission rates of 155 Mbps and up

3. 3 B-ISDN Capabilities n Interactive and distributive services n Broadband and narrowband rates n Bursty and continuous traffic n Connection-oriented and connectionless n Point-to-point or multipoint connections n Delay-sensitive or delay-insensitive traffic

4. 4 B-ISDN Assumptions n High capacity and high performance fiber-based transmission at physical layer n Flexible switching and multiplexing (i.e., “transfer modes”) u Transfer mode determines the rules for dividing up the usable capacity (bandwidth) of the network and allocating it to users (channels) u Choice: Asynchronous Transfer Mode (ATM) n Need to accommodate a wide variety of services, with diverse traffic mixes

5. 5 Simplified Protocol Stack B-ISDN ATM SONET Asynchronous Transfer Mode Synchronous Optical NETwork Broadband ISDN