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CCNA Voice 640-461 Official Cert Guide by Mike Valentine, Jeremy Cioara

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Chapter 1. Traditional Voice Versus Unified Voice

This chapter includes the following topics:

Where It All Began: Analog Connections: This section discusses the simplest type of modern voice communication: analog connections.

The Evolution: Digital Connections: Modern businesses quickly outgrow analog circuits. This section discusses the process of converting analog voice into digital signals and using digital circuits to send multiple calls over a single line.

Understanding the PSTN: Just about all voice circuits currently terminate at the world’s largest voice network, the PSTN. This section discusses the components of the PSTN, focusing specifically on PBX and Key Systems, and the methods used to connect to the PSTN.

The New Yet Not-So-New ...

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