单选题Which IP telephony component provides call processing, such as signaling, that in a traditional voice network is provided by switching equipment, such as a PBX?（）A Advanced call-handling software, such as Cisco UnityB Call-management hardware and softw
题目
单选题
Which IP telephony component provides call processing, such as signaling, that in a traditional voice network is provided by switching equipment, such as a PBX?（）
A
Advanced call-handling software, such as Cisco Unity
B
Call-management hardware and software, such as CiscoCallManager
C
Client-based software, such as CiscoSoftPhone
D
Voice gateways, such as the Cisco VG248 Analog Phone Gateway