What are three factors used to determine the amount of bandwidth that is required for a single VoIP call？（）

A.The gateway voice-capable device is configured to support call control directly performing call setup， call maintenance， and call teardown
B.The gateway voice-capable device has a local call routing table configured through a routing protocol.
C.The gateway voice-capable device relies on a call agent to support call control.
D.The gateway voice-capable device relies on a gatekeeper to support call setup， call maintenance， and call teardown.

A.CoS 0 = Best-Effort Data
B.CoS 1 = Best-Effort Data
C.CoS 3 = High Priority
D.CoS 4 = High Priority Data
E.CoS 5 = Voice Bearer
F.CoS 7 = Voice Bearer