The former one is to send out laser signals and the latter is to receive signals. As we all know, transceiver module has two ports, a transmitter port and a receiver port. There are loopback plugs for many different ports, including serial ports, Ethernet ports, and WAN connections.įiber loopback cable is often utilized to check whether the transceiver module is working perfectly as designed. In a word, it is a connection device that is plugged into a port to perform a loopback test. It provides system test engineers a simple but effective way of testing the transmission capability and receiver sensitivity of network equipment. The lookback cables can provide a simple and effective means of testing the capabilities of the network equipment, and they are typically used for fiber optic testing applications or network restorations.Ī loopback cable is also known as loopback plug or loopback adapter, which is a plug used to test physical ports to identify network issue. Do you know the loopback cable can be acted as a test tool in the telecommunication? Absolutely, the loopback signal is used for diagnosing the networking problem.

For testing applications, there are many tools for this function, such as visual faults locator, optical power meter, OTDR, etc.