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Fibre Channel: Why another interface?
March 2001
Introduction
For years, server-to-storage and server-to-server (or client) connections
have used separate technologies tailored to meet the unique
communication demands of each type of data transfer. One-to-one bus
interfaces, such as SCSI, are used for high-speed, high-volume transfers
between data storage devices and high-performance servers, PCs, and
workstations. Parallel bus technology provides extremely reliable,
high-speed block-based transfer for large amounts of data between a host
and its storage devices (typically disks and tape drives) over relatively
short distances.
Traditional IP-based networks, such as 10/100 BaseT Ethernet, are used in
LANs (local area networks) for server-to-client connections. Networks
provide file-based data transfer between many different types of devices
using a wide variety of command protocols. Optimized to provide extremely
flexible interconnections, networks are typically used for long-distance
communications at relatively slow data rates.
With the advent of the Internet, e-commerce, and a host of other
data-intensive applications, the ability to reliably move vast amounts of
data quickly over long distances and have it accessible to a large number
of users simultaneously has become increasingly important. More than
ever, companies strive to make the most of their IT dollars by sharing data
storage resources among many different servers. Futhermore, as the
amount of storage capacity increases, ease of management and scalability
become essential.
Neither SCSI nor traditional IP network technology can adequately address
the data transfer and storage requirements of todays computing
environments. A new interface that provides fast, reliable data transfer over
longer distances is needed. Fibre Channel, already in use for long-distance
system-to-system interconnection, is ideally suited to meet the data
transfer requirements of data storage on large networks.
Bus versus network
Today there are two basic types of technology used for system
interconnections: the bus (or I/O channel), typically used to attach a limited
number of peripherals such as tape drives to an individual system, and the
network, typically used to interconnect multiple systems and peripherals.
Each technology has its strengths and limitations; alone, neither
adequately fulfills the requirements for reliable, high-speed transfer of vast
quantities of data.
Parallel bus interfaces, such
as SCSI, and network
interfaces, such as 10/100
BaseT Ethernet, were
developed to fill different data
transfer needs. Neither of
these interfaces can
adequately address the data
transfer and storage
requirements of todays
computing environments.
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