December 2007
Intermediate to advanced
432 pages
9h 36m
English
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Chapter . Voice over IP
Making Calls over the Web
Traditionally, voice traffic traveled across circuit-switched connections of the PSTN. Corporate customers often had so many phone lines that they often deployed their own telephone exchanges using private branch exchange (PBX) networks or networks of private lines and time-division multiplexers (TDM). Although they had trunks into the PSTN (trunks are PSTN connections that can carry dozens of calls), these traditional networks tended to be proprietary, closed systems that were expensive to maintain, upgrade, and scale.
Voice over IP (VoIP) provides voice services such as phones, call routing, and voice mail using the data network. Thus, both the data and voice networks can converge into a single ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.