ZyXEL Communications MAX218M2W, Руководство пользователя

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MAX208M2W Series User’s Guide
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H A P T E R
9
The VoIP General Screens
9.1 VoIP Overview
The VOICE > General screens allow you to set up global SIP and Quality of
Service (QoS) settings.
VoIP (Voice over IP) is the sending of voice signals over the Internet Protocol. This
allows you to make phone calls and send faxes over the Internet at a fraction of
the cost of using the traditional circuit-switched telephone network. You can also
use servers to run telephone service applications like PBX services and voice mail.
Internet Telephony Service Provider (ITSP) companies provide VoIP service. A
company could alternatively set up an IP-PBX and provide it’s own VoIP service.
Circuit-switched telephone networks require 64 kilobits per second (kbps) in each
direction to handle a telephone call. VoIP can use advanced voice coding
techniques with compression to reduce the required bandwidth.
9.1.1 What You Can Do in This Chapter
• The Media screen ( Section 9.2 on page 135 ) lets you set up and maintain
global VoIP settings on the MAX208M2W Series.
• The QoS screen ( Section 9.2 on page 135 ) lets you set up and maintain QoS
settings for voice traffic flowing through the MAX208M2W Series.
9.1.2 What You Need to Know
The following terms and concepts may help as you read through this chapter.
Voice Coding
A codec (coder/decoder) codes analog voice signals into digital signals and
decodes the digital signals back into voice signals. The MAX208M2W Series
supports the following codecs.