FE interface of ZXCTN6100 can act as NNI interface for use in networking.（)

A.It supports 4-channel channelized STM-1/OC-3 interface

B.The channelized interface supports TDM.

C.It implements the POS fram

D. encapsulation or de-encapsulation of the data flow.

E.It supports clock synchronization.

A.1

B.2

C.3

D.4

A.Cross-connect clock main control board

B.GE optical interface board

C.XGE optical interface board

D.FE electrical interface board

A.ZXCTN6100 (except for the V1.0 that does not support OSPF)

B.ZXCTN6200

C.ZXCTN6220

D.ZXCTN6320

接口(interface)是什么？