Fibre Channel Networks

- Fibre Channel

It seems that for years, the death of Fibre Channel (FC) has been speculated, as Fibre Channel over Ethernet (FCoE) or even IP networks would be the death knell for the more traditional storage protocol. However, Fibre Channel is still alive and kicking.

Fibre Channel is a high-speed data transfer protocol (commonly running at 1, 2, 4, 8, 16, 32, 64, and 128 gigabit per second rates) providing in-order, lossless delivery of raw block data. Fibre Channel is primarily used to connect computer data storage to servers in storage area networks (SAN) in commercial data centers. Fibre Channel networks form a switched fabric because the switches in a network operate in unison as one big switch. Fibre Channel typically runs on optical fiber cables within and between data centers, but can also run on copper cabling.

Fibre Channel technology supports both fiber and copper cabling, but copper limits Fibre Channel to a maximum recommended reach of 100 feet, whereas more expensive fiber optic cables reach up to 6 miles. The technology was specifically named Fibre Channel rather than Fiber Channel to distinguish it as supporting both fiber and copper cabling.

Fibre Channel does not follow the typical OSI model layering. It is split into five layers:

FC-4 – Protocol-mapping layer
FC-3 – Common services layer
FC-2 – Signalling Protocol
FC-1 – Transmission Protocol
FC-0 – PHY connections and cabling

Fibre Channel networks have a historical reputation for being expensive to build, difficult to manage, and inflexible to upgrade due to incompatibilities between vendor products. However, many storage area network solutions use Fibre Channel technology. Gigabit Ethernet has emerged, however, as a lower cost alternative for storage networks. Gigabit Ethernet can better take advantage of Internet standards for network management like SNMP.

 - Fibre Channel SFP vs. Ethernet SFP

The small form-factor pluggable (SFP) is a compact, hot-pluggable network interface module used for both telecommunication and data communications applications. 

Fibre Channel, also known as FC, is a high-speed network technology used to connect computer data storage to servers. However, copper limits Fibre Channel to a maximum recommended reach of 100 feet, whereas fiber optic cables reach up to 6 miles with more expensive cost. 

Fibre Channel SFP is more reliable than Ethernet SFP in terms of lossless protocol. Fibre Channel SFP can provide in-order and lossless delivery of raw block data while Ethernet SFP can’t. 

Fibre channel supports a transmission speed of 1, 2, 4, 8, 16, 32, and 128 Gbps. While, the speed of optical transceiver used in Ethernet ranges from Fast Ethernet of up to 100 Mbps, Gigabit Ethernet of up to 1000Mbps, 10 Gigabit of up to 10 Gbps to even some 40 or 100 Gbps today. 

Normally, a Fibre Channel SFP is more expensive than an Ethernet SFP. The former is more popular in big enterprise network while the latter is commonly used in small-to-medium businesses.

[More to come ...]