Looking for SFP Fiber Optic Transceivers? Learn basic facts about SFP modules. Pluggable transceivers are available in a variety of sizes and support a variety of cabling media and application speeds.


You will hear phrases such as GBIC, mini-GBIC, SFP, XFP and others. These support different speeds and have different form factors. A smaller version of the GBIC is called a mini-GBIC or SFP (small form factor pluggable) module. It serves the same purpose as the GBIC but has a smaller footprint. To support the smaller footprint, SFPs use LC connector interfaces. SFPs are also available for a 1000-Base-T connection with an RJ-45 interface.
Signal transmitting rate of the SFP transceivers range from 100 Mbps up to 4 Gbps or more, typical supported distance of such SFP transceiver modules can be from 0.5 km to 100 km. Typical wavelengths of SFP transceivers are 850 nm, 1310 nm and 1550 nm, however, there are also CWDM type SFP transceivers available.
SFP module is hot pluggable. This means that you can plug it in or out when the device is switched on. Even users can replace or install a SFP module. Compared with traditional modules this is a big advantage and simplifies maintenance. Fiber optic network or fiber-Ethernet network can easily be upgraded with SFP fiber transceiver modules

According to multi-source agreement between various manufacturers each SFP has a 256-byte memory map in accessible as I2C EEPROM. This EEPROM describes the transceiver's manufacturer, capabilities, standard interfaces, and other information. The memory is organized as a series of 8-bit bytes that can be addressed individually or sequentially. The serial I2C interface is the same as it is defined for the ATMEL AT24C02/04 EEPROMS.

SFP plus

SFP module has an advanced version of the small form pluggable transceivers, SFP plus. SFP plus modules are intended for use in 10 Gbps Ethernet and 8.5 Gbps Fibre channel applications. SFP plus module is more compact and suitable for applications where space is limited. SFP plus has lower power consumption, typically less than 1W. These modules come with managed digital optical monitoring  (DOM) and better performance in high temperature environment.

There are several industrial accepted standards for SFP plus and 10 Gbps networks. 10Gbase-SR (a mode of 10GBase-S) defines the SFP plus transceiver working with OM3 10 Gbps multimode fiber (850 nm laser) at 30 to 300 meters range using dark fiber, 10Gbase-LR (long range) defines the SFP plus transceiver working with single mode fiber (1310 nm laser) at 10 km range, and 10Gbase-LRM (long reach multimode) defines the FDDI multimode fiber at around 220 meters range.

Digital diagnostic monitor interface

Modern optical SFP transceivers support digital diagnostics monitoring (DDM) functions according to the SFF-8472. This feature is also known as digital optical monitoring (DOM). This feature enables you to monitor real-time parameters of the SFP module, such as temperature, optical output power, optical input power, laser bias current, and SFP transceiver supply voltage. This monitor interface is also accessible as I2C EEPROM.

Digital Optical Monitoring

Some newer optical transceivers support digital optical monitoring (DOM) functions. Those functions allow you to track in real-time the transceiver temperature, optical output power, optical input power, laser bias current, and transceiver supply voltage. Both, Digital Optical Monitoring and Digital diagnostic monitor interface are defined in the industry-standard SFF-8472 multisource agreement (MSA) - Diagnostic Monitoring Interface for Optical Transceivers.

Cisco SFP Transceivers

Cisco SFP transceivers adopt LC interface. Their size is only about half of the size of GBIC, therefore Cisco SFP fiber transceivers fit for dense network installations. The Cisco SFP transceivers cpmply with the multi source agreement SFF-8472. Cisco supplies various kinds of SFP fiber optic transceivers, including single mode, multimode and copper SFP; they come with various working wavelength and functions.  Cisco also supplies advanced CWDM SFP, DWDM SFP and SFP plus fiber transceivers. Cisco supplies the SFP fiber optic transceiver modules with excellent performance and reasonable price.

Many manufacturers offer equivalent Cisco SFP products. Usually, such equivalent  and compatible Cisco SFP products are manufactured and tested strictly according to high industrial standards. Because of compatibility you can use them with Cisco devices and equipment from other manufacturers. Most of those modules have digital optical monitoring function built in. In some cases the module has to be programmed with special data in order to function properly in equipment where original Cisco SFP modules were envisaged.

Omnitron SFP Transceivers

Small Form Pluggable (SFP) and 10 Gigabit SFP+/XFP optical transceivers from Omnitron are compact media connectors for various communication needs. Transceivers enable any network device to connect to various cables, either copper or fiber. The Omnitron modules support single-mode dual fiber, multimode dual fiber, single-mode single-fiber, Coarse WDM and UTP copper cabling. i

Pluggable optical modules eliminate the need to maintain surplus modules of various specific media types for network upgrades or repairs if the module fails. Therefore pluggable optical modules reduce network equipment inventories and cost. By providing interchangeable fiber and copper connectors which can easily adapt to and modify any existing network, SFP modules enable network upgrades and growth. With all Omnitron SFP Transceivers digital diagnostic capability comes as standard feature.

RAD SFP Transceivers

RAD’s SFP transceivers are hot-swappable, I/O transceiver units for optical and electrical media conversion. They provide a wide range of detachable interfaces to multimode and/or single-mode optic fibers and UTP/coaxial electrical cables. They also allow the transport of Fast Ethernet and Gigabit Ethernet LAN packets over TDM-based WANs, as well as the transmission of E1/T1 streams over packet-switched networks. In addition to facilitating efficient design of host devices and flexible network planning, RAD’s miniature SFP transceiver units enable significant savings in system maintenance and upgrade costs.

3Com SFP Transceivers

3Com SFP transceivers are industry-standard, hot-swappable devices that plug into a Gigabit or Fast Ethernet slot, linking it with either a fiber- or copper-based network. Selected 3Com switches are supported. 3Com SFP modules can be used in many 3Com switches and modules which support SFP modules. SFPs can be mixed and matched on a given switch to maximize flexibility. However, the connection and associated port at the remote end must match the chosen SFP connection type.

SFP Transceivers from Huihong Technologies

Huihong Technologies Limited specialize in manufacturing of fiber optic products - the company is known for the excellent products quality, competitive prices, fast delivery and good service. Their SFP transceivers are compatible with the fiber optic products from most manufacturers, including CISCO. Check their list of equivalent SFP fiber optic transceivers. For each Cisco type you can find a compatible SFP transceiver.

There is a general rule regarding SFP transceivers. If two modules have exactly the same specifications then they are at least in theory equivalent. This means that you could exchange them. Unfortunately this doesn't always work. All SFP modules have identification stored in the EEPROM including manufacturer and model name. Some equipment checks if the SFP module is from the authorized manufacturer. If you are able to change this data to match the original module then you can use a replacement SFP module which is usually much cheaper. Check offers, some dealers can do it for you.