Fiber channel workstations interconnections through ATM local network

The Fibre Channel Standard (FCS) is an emerging standard for providing a common efficient transport vehicle for existing channel protocols like the Intelligent Peripheral Interface (IPI), Small Computer System Interface (SCSI) and High Performance Parallel Interface (HIPPI). This paper deals with the interconnection issue of FCS-based workstations through an ATM switch. In particular, the design of a high throughput FCS/ATM InterWorking Unit (IWU) is presented. A specialized segmenting and reassembly protocol, named FAP, has been defined to guarantee the transparency of the end-to-end FCS protocols. The hardware and software characteristics of the IWU are described and its performance evaluated by a simulation study. Performance evaluation has focused on FCS flow control functions with the twofold aim to determine the impact of IWU on the protocol parameters (e.g. timeouts, window size, etc.) and to assume reliable data for a suitable dimensioning criteria for IWU elements (e.g. segmenting and reassembly buffers). Results obtained show that throughput values approaching the available ATM link bandwidth can be achieved depending on the discipline utilized to manage the IWU buffers.