Section 1. Introduction to Voice Gateways

Modern enterprise network designs need to support the transmission of voice traffic. While more and more traffic in the business world is originating from VoIP products such as IP phones, there is still a need to interface with the traditional telephony world. Interfaces such as T1/E1 PRI for public switched telephone network (PSTN) connectivity, analog lines for PSTN backup, and analog stations for traditional devices such as fax machines and modems are still required. For this purpose, devices known as gateways provide the transition between the packetized IP telephony devices and the traditional telephony devices.

The term Voice over IP, or VoIP, is used to describe the transmission of voice over a ...

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