Gigabit Interface Converters

A Gigabit Interface Converter, or GBIC for short is a network transceiver used to convert electrical data signals into optical signals for transmission across fiber optic links. The common optical links are Gigabit Ethernet or Fiber Channel. Some of these channels can be multiplexed together onto CWDM or DWDM systems.

The GBIC standard was first implemented in the 1990's and is still used today because of its flexibility, ease of use and the fact that a lot of Gigabit Interface Converters are designed to be hot-swappable. GBIC is not proprietary standard, but is defined by the Small Form Factor Committee. The standard supports an extensive range of media from twisted pair copper to multi-mode and single-mode optical fiber over distances from a few metres to hundreds of kilometers, depending on the type and quality of the fiber and transceivers. A popular version of the GBIC is the mini-GBIC, often referred to as an SFP or Small Form Factor Pluggable Transceiver. In fact almost all GBICs today are SFP.

There are a wide range of SFP transceivers available to allow connection to a wide variety of optical fiber and wavelengths. Short haul fiber connections commonly use 850nm over multi-mode fiber at distances up to around 550 Meters, whereas Long Haul fiber often uses 1310nm over single-mode fiber at distances up to around 10 Kilometres. Other wavelengths are used for even greater distances and CWDM and DWDM GBICs are also available.

The reason the GBIC became so popular was because of the fact that by providing GBIC receptacles within networking equipment such as Ethernet Switches and Routers, these interfaces provided flexibility of connectivity because network engineers and administrators could select a Gigabit Interface Converter to connect to a network regardless of the media type. This meant that devices that had flexible hardware configuration had a potentially longer life in the network.

Another version of the SFP known as SFP + is also available and is also know as the enhanced small form-factor pluggable SFP. It was designed for higher speed fiber connections up to 10 Gbps such as 10G Ethernet and fast Fiber Channel connections. Another reason for the development of the mini-GBIC was one of space. Because of their smaller size, more interfaces can be included on standard, modular network equipment such as routers and switches.

Most of the major network hardware manufacturers have adopted the GBIC and mini-GBIC standard and a wide range of these products are available for sale.