Which term best describes voice communications over an IP network?

Which term best describes voice communications over an IP network?

• A. VoIP
• B. PSTN
• C. ISDN
• D. PBX

Answer: (A)

Voice communications over an IP network is described by VoIP, because VoIP specifically means sending speech as data packets over Internet Protocol networks. It involves converting voice into packets, using signaling to set up calls (such as SIP or H.323), and delivering the audio with protocols like RTP. This approach lets calls travel over the same networks that carry data, whether on the public internet or a private corporate network, often reducing costs and enabling easier integration with other IP-based services. By comparison, the traditional PSTN is the old circuit-switched public telephone network, ISDN is digital but still relies on circuit-switched channels, and PBX refers to a private branch exchange system for routing calls—not a term that describes voice over IP itself.

Voice communications over an IP network is described by VoIP, because VoIP specifically means sending speech as data packets over Internet Protocol networks. It involves converting voice into packets, using signaling to set up calls (such as SIP or H.323), and delivering the audio with protocols like RTP. This approach lets calls travel over the same networks that carry data, whether on the public internet or a private corporate network, often reducing costs and enabling easier integration with other IP-based services. By comparison, the traditional PSTN is the old circuit-switched public telephone network, ISDN is digital but still relies on circuit-switched channels, and PBX refers to a private branch exchange system for routing calls—not a term that describes voice over IP itself.