单项选择题
A.Client-based software, such as CiscoSoftPhone
B.Voice gateways, such as the Cisco VG248 Analog Phone Gateway
C.Call-management hardware and software, such as CiscoCallManager
D.Advanced call-handling software, such as Cisco Unity
单项选择题 Which software-based security threat is typically spread from user to user via e-mail?（）
单项选择题 Which Cisco product is a hardware component that supports content filtering and other gateway security functions for the Catalyst 6500 Series?（）
单项选择题 Wide Area Network (WAN) is a computer network that covers a broad areA. Which statement is correct for wide-area network (WAN)?（）