Essential Information About SFP Modules

Introduction of SFP Modules

SFP, short for Small Form-factor Pluggable, is a compact optical transceiver module used in optical communications. SFP optical transceivers are hot-swappable, compact media connectors that provide instant fiber connectivity for your networking gear. They are an effective way to connect a single network device to a wide variety of fiber cable distances and types. SFP optical module is mainly composed by laser TOSA (including the transmitter and receiver, ROSA), circuit board IC and other external accessories. It is expected to perform at data speeds of up to five gigabits per second (5 Gbps), and possibly higher. Because SFP modules can be easily interchanged, electro-optical or fiber optic networks can be upgraded and maintained more conveniently than has been the case with traditional soldered-in modules.

The types of SFP Modules

SFP transceivers are able to provide an excellent amount of variation to consumers. They have a various different transmitters and receivers types, allowing users to decide on the appropriate SFP transceiver for each link to offer the required optical reach.Optical SFP modules are commonly available in two different categories:

Fiber SFP

Fiber SFPs contain only the laser driver, photodiode receiver and some simple AGC logic. Whatever comes to the LVDS input of such an SFP, goes out to the fiber preserving exactly the same protocol and timing (+/- the jitter).
For multimode fiber, with black or beige extraction lever
There is SX-850nm, for a maximum of 550m at 1.25Gbit/s (gigabit Ethernet) or 150m at 4.25Gbit/s (Fibre Channel)
For singlemode fiber, with blue extraction lever
There is LX-1310nm (for distances up to 10km), EX-1310nm (for distances up to 40km) and ZX-1550nm (for distances up to 80km, with green extraction lever)

Copper SFP

Copper SFPs are deigned to be used in copper networks. Copper SFPs are on the other hand, not only transceivers. They convert the 8b10b protocol used in 1000Base-X (SFP interface) to a much more complex 1000Base-T physical layer protocol. Driving a CAT5/6 copper directly with 1.25 GBaud signal as in 1000Base-X is not possible.
For copper twisted pair cabling
1000BASE-T- these modules incorporate significant interface circuitry and can only be used for gigabit Ethernet, as that is the interface they implement. They are not compatible with (or rather: do not have equivalents for) Fiber channel or SONET.

Benefits of SFP Modules

SFP Transceiver Module is also hot pluggable, which make it easy to change and easy for maintenance compared with traditional modules. Meanwhile, they are compatible to multiple setups across both fiber optic and copper channels. When you need long or short distance communication, SFP transceivers play an important role in that.
SFP Transceiver Module is regarded as the upgrade version GBIC, unlike GBIC, SFP Transceiver Module saving more space, and it interfaces a network device mother board (for a router, switch, media converter or similar device) to a fiber optic or copper networking cable. It is a popular industry format supported by many network component vendors.
SFP transceivers module are designed to support SONET, Gigabit Ethernet, Fiber Channel, and other communications standards. SFP transceiver modules make the fiber optic network or fiber-Ethernet network easier to upgrade or maintain users to replace a single SFP module during the process, rather than replace the whole board with many modules on it.