• A data transfer interface technology that combines several common protocols including IP and SCSI, allowing it to merge high-speed I/O and networking functions in a single technology.
  
  
• An open standard defined by ANSI and OSI.

What It Really Is
Fibre technology is a high-performance interface technology designed for bi-directional, serial data communication between servers, mass storage subsystems and peripherals through hubs, switches and point-to-point connections.

General Fibre Benefits:

• High Data Transmission Rates - up to 2 Gigabits/sec. now; 10 Gigabits/sec. coming soon
  
  
• Multiple-Device Connectivity - connect up to 126 devices to 1 "loop"; up to 16 million devices using a switch
  
  
• Long-Distance Connectivity - up to 10 kilometers (optical)
  
  
• Low CPU Overhead
  
  
• No Server Downtime Required to Reconfigure/Add Devices
  
  
• Easily Scalable for Increased Storage
  
  

Comparison Summary

Fibre Channel	SCSI
FC-AL is highest performance storage interconnect on the market today. A choice for users that require high-reliability, hot pluggability & flexible connection to a lot of data (fast and far). SCSI protocol limits the distance between the storage and the host.	Lower-cost alternative for users with less-stringent performance and scalability requirements. Still handles small I/Os more efficiently. FC protocol overhead can bottleneck throughput when many small I/Os are requested.

Copper vs. Optical Connections

Copper	Optical
Supports 1Gbps operation More economical Cable lengths limited to under 30 meters. Un-equalized 28AWG: 5m Equalized 22AWG: 15m HSSDC; HSSDC2 Connectors; SFP Module	Supports 1 or 2Gbps operation Very expensive Up to 500 meter cable lengths possible. 62.5/125µm: 150m 50/125µm: 300m LC Connectors; SFP Modules Less/not susceptible to EMI

SFP Modules

• Transceivers
  
• Physical interface between cable connector & PBP circuitry
  
  

• Simplest of three topologies
  
• Only two FC devices connected directly together
  
• The "Transmit" port of one device connects to the "Receive" port of other device, and vice versa
  
• No sharing of media - devices each benefit from total link bandwidth
  
• Link initialization required before communication begins
  

Arbitrated Loop

• Most dominant, yet most complex FC topology
  
• Cost-effective way of connecting up to 126 ports in a single network without requiring a Fabric switch
  
• Media is shared among devices, limiting each device's access.
  
• Not all devices are required to operate on an Arbitrated Loop; the added functionality is optional.
  
• All devices must be loop devices.

• Used to connect as many as 16,777,216 devices in a cross-point switched configuration.
• Benefit is that many devices can communicate at the same time; media is not shared.
• Requires purchase of a switch.