問83
頻出度★★★
スマートフォンなどで, 相互に同じアプリケーションを用いて, インターネットを介した音声通話を行うときに利用される技術はどれか。
令和5年度 ITパスポート試験 問83
テクノロジ系ネットワーク › ネットワーク応用
This question's explanation and your answers so far.
解説
問 83
Incorrectア
MVNO (Mobile Virtual Network Operator) refers to a “type of carrier” that owns no network line facilities of its own and instead leases another company’s mobile network to provide communication services; it is not in itself a technology for making voice calls.
Incorrectイ
NFC (Near Field Communication) is a wireless communication technology used over very short distances of a few centimeters, for contactless IC cards and tap-to-use payments and data exchange. It is not a technology for voice calls over the Internet.
Incorrectウ
NTP (Network Time Protocol) is a protocol for accurately synchronizing the clocks of devices on a network; it has nothing to do with voice calls.
- エ
正解 Choice エ, “VoIP (Voice over Internet Protocol),” is a technology that converts voice into digital data and sends and receives it as packets over an IP network (the Internet). Installing the same calling app on smartphones and making voice calls over the Internet is exactly a use of VoIP, which matches the conditions in the question.
ここがポイント
- VoIP converts voice into IP packets and sends and receives them over the Internet; it underpins IP telephony and app-to-app calling.
- MVNO (a type of carrier), NFC (short-range wireless), and NTP (time synchronization) are all network-related abbreviations, but they play different roles, so distinguish them by their definitions to avoid confusion.
用語