Improving the technology of data transfer has led to the emergence of an optical fiber network, where to connect devices it is necessary to use special equipment - an SFP transceiver. SFP modules have replaced the more cumbersome GBIC equipment and are used in telecommunication lines with data streaming speeds above 100 Mbit per second.
Destination
SFP transceivers are used as transceiver equipment. In other words, they act as intermediaries between an optical fiber cable or unshielded twisted pair cable and a network device board — a switch, modem, or router. The main advantage of the module is the connector is very small. Thanks to this, an SFP transceiver with a width of only 20 centimeters can accommodate up to 20 slots.
The equipment is used for high-speed data transfer (more than 10 Mbit per second) using the following technologies: SDH and Fiber Channel. In addition, there is equipment that can operate with three types of broadcast signal.
Types of SFP Transceivers
Depending on the tasks, type of fiber optic cable, as well as the equipment used, all SFP modules are divided according to several criteria:
- Data transfer rate. An ordinary SFP transceiver retransmits a signal at a speed of 100 Mb / s and 1 Gb / s, standards SFP + and XFP - up to 10 Gb / s.
- Type of connector used. SC-slot is used to connect a single-fiber cable, where the reception and transmission of information occurs on a single fiber, and the LC-connector - for two-fiber, where the reception and transmission of signals is carried out through its channels.
- Type of fiber. An SM transceiver is used to connect to a single-mode wire, and MM modules for multimode wires.
- The highest transmit power. This characteristic varies in the range of 1310 nm and 1550 nm for single-mode connection, and within 850 nm and 1310 nm for multimode cables.
Each SFP transceiver has a specific optical budget, or signal transmission / reception range. As you pass through the cable, the light signal fades. The difference between the maximum distance at which the module is able to send a signal and the power of the received light flux is called the optical budget. These data are indicated in the transceiver data sheet in dB.
Features of working with modules
During data transmission, the SFP module emits a light signal in the invisible spectrum (there is a special laser inside the equipment for this). Therefore, it is strictly forbidden to look into the “eye” of the device in order to avoid damage to the retina.
When connecting the SFP transceiver, it is necessary to wear an antistatic wristband, after connecting it to the case. Otherwise, electrostatic discharge can damage the device.
In addition, the “eye” of the laser is sensitive to dust, so do not remove the protective caps before connecting the device to the network. To extend the life of the module, avoid unnecessarily removing the cable from the connector.
Rules for choosing SFP modules
You must choose the SFP transceiver according to the specifications of your fiber optic cable. In this case, it is necessary to focus on several issues. First, you need to accurately determine the optical budget. For this, special devices are recommended. When there are none, you can find out this value “by eye”, it is enough to know the distance between the reception and transmission points with an accuracy of one kilometer.
Secondly, determine the type of latch on the board of your network device. The optical SFP transceiver must be chosen with exactly the same lock. Otherwise, you simply cannot use the module. Currently, there are three types of devices with latches on the market: Button, Mylar Tab, Bale-Clasp. You can determine the type visually.