In the WDM networking design, as long as there are enough EDFA cascades to compensate for the loss of optical power during transmission. Then the system can transmit a long distance without restriction.

Two PIU/APIU boards use the hot backup mode to supply power to the system on the OSN 1800 device, when a PIU/APIU board fails, the system can still work normally.

When 10-minute error-free test is performed on a certain wavelength division channel, the local end uses the SDH analyzer to interconnect with the client-side interface of the OTU board. The peer OTU client-side interface needs to perform fiber self-loop. When you are self-looping, you must add solid decay.

In the sub-(wave) characterization test, what kind of standard does the isolation test require?

The packet protection features supported by the OSN 1800V include _______. (Multiple choice)