The four-wave mixing phenomenon is the most serious when the optical signal propagates in the optical fiber of which of the following option, and the transmission damage caused by it is also large?

It is necessary to perform the () operation before querying the error code and optical power on the network management system, otherwise the corresponding teaching data cannot be queried.

What parameter does the ECC protocol use as the unique identifier of the network element, and NCE also uses it as the keyword for retrieval when identifying different network elements in the interface and database?

In the characteristic test of the splitter (multiplexer), what standard should the isolation test meet?

In the fault handling scenario, human misoperation will lead to business interruption. Which of the following descriptions about possible causes is wrong?