The Architecture and Implementation of a High-performance FDDI Adapter

The architecture and With the advent of fiber implementation presented distributed data interface in this paper are for the (FDDI) technology, Digital DEC FDDIcontroller 400, saw the need to define Digital's high-performance, an architecture for a XMI-to-FDDI adapter known high-performance adapter as DEMFA. This adapter that could transmit data provides an interface 30 times faster than between an FDDI LAN and previously built Ethernet Digital's XMI-based CPUs, adapters. We specified presently the VAX 6000 a first generation FDDI and VAX 9000 series of data link layer adapter computers.[1,2] DEMFA architecture that is implements all functions capable of meeting the at the physical layer and maximum FDDI packetmost functions at the data carrying capacity. The link layer.[3,4] DEC FDDIcontroller 400 We begin the paper by is an implementation differentiating between of this architecture. an architecture and an This adapter acts as an implementation. Then we interface between XMIpresent our project goal based CPUs, such as the VAX and analyze the problems 6000 and VAX 9000 series encountered in meeting of computers, and an FDDI this goal. Next we give a local area network. historical perspective of Fiber distributed data Digital's LAN adapters. interface (FDDI) is We follow this discussion the second generation by describing in detail local area network (LAN) the architecture and technology. FDDI is defined implementation of DEMFA. by the American National Finally, we close the paper Standards Institute (ANSI) by presenting some results FDDI standard and will of performance measurement coexist with Ethernet, at the adapter hardware the first generation LAN level.