You are the network engineer at domain.com. Youto connect a Cisco voice gateway to a PBX or the PSTN via ISDN (PRI, QSIG, BRI).
What are two attributes of the PBX/PSTN switch that must be known to understand which features to configure on the voice gateway to connect successfully to it? (Choose two)

A.
Whether Q.921 or Q.931 is supported by the PBX/PSTN switch.

B.
Whether Symmetric mode is supported by the PBX/PSTN switch.

C.
Which PRI/BRI switch-type is supported by the PBX/PSTN switch.

D.
Whether network or user side is supported by the PBX/PSTN switch.

E.
Whether wink, delay dial, or immediate dial is supported by the PBX/PSTN switch.