Depending on the networking devices and interfaces used in the data center, you can use a number of fiber optic cable connectors, as follows:
- ST
- SC
- LC
- FC
- MT-RJ
A relatively old but still used type of fiber connector is the ST (Straight Tip) connector, which is a bayonet-type connector, meaning you have to push it into the transceiver and turn it to activate the integrated lock system. The same process is carried out when unplugging the connector, meaning you cannot just simply pull it out of the network device. An example of ST connectors is shown in Figure 15.1 below:
Figure 15.1 – ST Connectors
ST connectors are usually used on old devices and on devices they need to stay plugged into in the event of an accident. The main disadvantage of ST connectors is their size, as they are bulky compared with newer connector types. Because of this they might not be practical for use in high-cable-density environments.
A newer type of fiber connector is the SC (Subscriber Connector) connector, although people also refer to it as a Standard Connector or Square Connector. These connectors also have a lock system but it is an automatic one and it is not as secure as the ST lock system. An example of an SC connector is shown in Figure 15.2 below:
Figure 15.2 – SC Connector
SC connectors often can be found in pairs of two (one Transmit and one Receive fiber), connected with a plastic bracket, to make installation easier and not to avoid confusion between the Transmit and the Receive sides. Such a connector can be seen in Figure 15.3 below:
Figure 15.3 – SC Double Connector
The latest type of fiber connector is the LC (Lucent/Little/Local Connector) connector. This has replaced older ST and SC models in network environments because of its small size. LC connectors usually can be found in pairs, with a small bracket that unites the Transmit and Receive fibers and that can be installed in a single connection into the network device. These connectors also have a small lock system that automatically activates when it’s plugged in, but it has to be manually disabled when the connector is unplugged by pressing on the upper plastic bracket. LC connectors allow a large amount of fiber to fit in its small space comparing to ST/SC connector types. An example of an LC connector is shown in Figure 15.4 below:
Figure 15.4 – LC Connector
The MT-RJ (Mechanical Transfer-Registered Jack) connector is one of the smallest fiber optic connector types available. It was created to use the same amount of space in a network device as a standard copper RJ45 connector. To achieve this, both the Transmit and the Receive fibers are embedded into a single small enclosure, as can be seen in Figure 15.5 below:
Figure 15.5 – MT-RJ Connector