ENUM is a technology protocol created by the IETF that will tie the tradition telephone network with the Internet in the NGN.

在下一代网络中，由IETF定义的技术协议ENUM是传统电信网和互联网的连接纽带。

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Silent Phone deploys the ZRTP peer-to-peer encryption protocol which is recognized as the leading standard for secure end-to-end communication in a Voice over Internet Protocol (VoIP) telephone call.

FORBES: Silent Circle Adds Android For Encrypted Voice And Video Calls

And if you've ever wanted to seriously used a Wi-Fi network to make voice telephone calls using Voice Over Internet Protocol technology (VOIP), your network will need a feature called QOS or Quality Of Service.

FORBES: Magazine Article