In the SDH multiplexing structure, the rate represented by VC-12 is ().

Which of the following is a functional unit that provides serial data to the interface and system associated with the orderwire telephone?

U2000 network management supports multiple external interfaces. When connecting with the network management of other manufacturers' equipment, which of the following interfaces can be used?

When the SNCP ring consisting of four Optis OSN 2500 devices has a rate of 25 Gbt/s, the network's service answer stars can carry up to ()2Mt/s Signal.

For the B1 byte, which of the following statements are correct? (Multiple choice)