Page 8 of 18 Fibre Channel: Why another interface? March 2001 The Fibre Channel solution While bus and traditional network technologies are excellent solutions in the environments for which they were originally designed, neither adequately meets the challenges of today’s data storage environments. Fibre Channel was specifically designed and optimized for high-speed, server-to-storage and server-to-server data communication. This new interface combines the performance and data handling characteristics of a bus with the flexibility and distance capabilities of a network, and improves on both. Fibre Channel provides each server attached to Fibre Channel network with the kind of high-performance data transfer that is normally reserved for directly connected devices, but over significantly longer distances. Fibre Channel supports data rates that are comparable to or better than SCSI (up to 200 MB per second or 120,000 pages of text per second versus 160 MB per second for Ultra160 SCSI). Because it uses serial data transmission, Fibre Channel can transfer data up to 25 meters per link using copper cable and up to 10 kilometers (6.2 miles) per link using single-mode fiber optic cable (compared to 25 meters for a dedicated Ultra2 SCSI bus between two devices and only 3 meters for a multi-device bus). The following table summarizes the characteristics of the new Fibre Channel interface that make it ideal for building large data storage networks. Fibre Channel combines characteristics of a bus and a network Bus characteristics Network characteristics •    High-performance data transfer (up to 200 MB per second) •    Low error rates •    Hardware signal processing and error handling resulting in low processor overhead •    Separate cables for transmitting and receiving data •    Reliable data transmission protocols to ensure that packets are not lost or damaged during transmission •    Support for existing high-level command protocols like SCSI •    Serial data transmission •    Increased distance between devices (up to 10 kilometers) •    Simple cables and connectors •    Encapsulated data allows heterogeneous systems transferring many different types of data to share the network •    Support for connecting a large number of devices or nodes (up to 126 in an arbitrated loop, over 16 million in a switched fabric) •    Unique identifiers for each device •    Support for hubs and switches to create configurable networks (fabric) for robust, reliable, scalable data transfer between multiple servers and storage •    Support for standard network architectures allows devices to be monitored and maintained using familiar network technologies Fibre Channel combines the advantages of parallel bus and network technologies and improves on both. p1   p2   p3   p4   p5   p6   p7   p8   p9   p10   p11   p12   p13   p14   p15   p16   p17   p18