Technology interworking for SMDS: from the DXI/SNI to the ATM UNI

As service providers introduce asynchronous transfer mode (ATM) into their networks, they are faced with the issue of technology interworking: for a given service, can a customer who has an ATM user-network interface (UNI) communicate with a customer who does not have an ATM UNI? For switched multimegabit data service (SMDS), technology interworking is well defined. In fact, SMDS is supported by several technology platforms that can interwork with each other. The three major platforms which support SMDS are: a frame-based platform based on the SMDS data exchange interface (DXI), a cell-based platform based on the IEEE 802.6-1990 standard, and a cell-based platform based on ATM. This article examines how SMDS is supported by each of these platforms and how these platforms interwork. Furthermore, this article presents how the major interworking functions required for these platforms appear to be straightforward for suppliers to implement,