A multimedia STM switch prototype

There is no doubt the concept of ATM (asynchronous transfer mode) has gripped the technical community and has raised the hope for truly integrated voice, data, imaging, and video services. Such a dream was never possible before because of the diverse bandwidth requirements of each service type. Existing narrowband switches could not possibly keep up with widely varying channel bandwidth or the enormous aggregate bandwidth required. New methods of signaling would also be required to support new broadband services. The signaling itself might need varying degrees of bandwidth, and would likely be carried in the same stream as the data, yet be easily distinguishable. A common unit of information in the form of a 53 byte cell, including a header that helps determine the final destination of that cell, was adopted as the broadband integrated services digital network (B-ISDN) standard. While a great deal of work has progressed on ATM since the standard was adopted, there remains a camp that voices concerns as to the technical challenges that face deployment of ATM for certain services. In particular, concerns have been raised questioning the use of ATM networks to effectively route traffic that is constant-bit-rate (CBR) in nature and highly correlated. Voice and video services are of particular interest because of their potential economic markets. While it is almost certain that ATM, given enough time and resources, will prove its ability to handle these services, it behooves us to look for alternatives based on experience with existing telecommunications products. We present work completed in this area