What is the benefit of the Cisco ASA phone proxy feature?

A.
allows businesses to securely connect their Cisco Unified Presence clients back to their enterprise networks or to share presence information between Cisco Unified Presence servers in different enterprises

B.
allows telecommuters to connect their IP phones to the corporate IP telephony network securely over the Internet, without the need to connect over a VPN tunnel

C.
allows businesses to configure granular policies for SCCP traffic, such as enforcing only registered phone calls to send traffic through the Cisco ASA security appliance and filtering on message IDs to allow or disallow specific messages

D.
enables deep inspection services for SIP traffic for both User Datagram Protocol (UDP) and TCP-based SIP environments, thus providing granular control for protection against unified communications attacks

E.
enables inspection of the RTSP protocols that are used to control communications between the client and server for streaming applications

F.
enables advanced H.323 inspection services that support H.323 versions 14 along with Direct Call Signaling (DCS) and Gatekeeper-Routed Call Signaling (GKRCS) to provide flexible security integration in a variety of H.323-driven VoIP environments