Fibre Channel FAQ
This FAQ is an attempt to explain Fibre Channel and answer specific questions about the technology.
What is Fibre Channel?
Fibre Channel is a serial data transfer technology developed by a consortium of computer and mass storage vendors and is now standardized by ANSI.
What is Fibre Channel used for?
Fibre Channel is used for Storage Area Networks (SANs) to provide fast access to mass storage from servers. Fibre Channel also allows TCP/IP to operate via IPFC. Fibre Channel is being adapted to work across Ethernet. SATA is being adapted to work across Fibre Channel.
What speed is Fibre Channel?
Fibre Channel links run at 1 Gb, 2 Gb, and 4 Gb per second. 8 GB and faster speeds are under development. Note that the Fibre Channel protocol between a Host Bus Adapter (HBA) and any attached devices such as mass storage, hubs, or switches is a 10 bit protocol. The 8 bit data stream is encoded to a 10 bit protocol and so a direct comparison of throughput at the link layer is not directly possible.
As of February 2008, 8 Gb is now shipping.
What host bus architectures are supported?
Fibre Channel HBAs can be purchased with PCI 2.0, PCI 2.1, PCI 2.2, PCI 2.3, PCI 3.0, PCI-X 1.0, PCI-X 2.0, and PCIe 1.x.
What operating systems are supported?
Fibre Channel HBAs are available in the following operating systems (OS) (no particular order):
- Windows NT 4.0
- Windows 2000 Server
- Windows 2000 Professional
- Windows XP
- Windows Vista
- Windows Server 2003
- Linux
- Solaris
- HP-UX
- AIX
- MacOS X
- MacOS X Server
Is Fibre Channel suitable for home use?
While there is no reason Fibre Channel could not be used for in the home, the cost associated with the HBAs and the mass storage make it impractical. HBAs cost upwards of $800US and the mass storage runs in the thousands of dollars (US). Deals can be found on eBay. This technology is best suited for server use.
What types of cables are used to connect Fibre Channel?
When Fibre Channel first came to market, it was mostly copper twisted pair wiring. As the speed increased, it became obvious that copper cabling was not appropriate due to cross talk the limited distances allowed. All Fibre Channel now (2 Gb and faster link speeds), use fiber optics. Most cabling are multimode cables (short wave) using 50/125 or 62.5/125 cables allowing for up to 150 meters. For longer distances (thousands of kilometers), single mode cables (long wave) are used.
You keep talking about links. What are links?
Links are the cabled connection between Fibre Channel devices. For example, when you connect a cable between an HBA in a server and a switch, this is the link. The link speed will be 1, 2, 4, or 8 Gb per second.
The connectors look the same. Can Fibre Channel and Gigabit Ethernet with optical connectors work together?
While some of the lower lever protocols (primitives) that are used to bring the link up are the same, the two technologies are not directly compatible. You need a bridge or router that understands both protocols and can translate between the two.
