AV Technology - October 2008 - (Page 32)

UNDERSTANDING IoIP Page 31, middle: Barix’s Annuncicom products deliver high-quality MP3, G.711, and uncompressed audio over standard network infrastructure. Page 31, left: Extron offers two types of hardware modules: the IPI 100 Series (shown), which require an IP intercom-enabled MLC 226 IP MediaLink Controller for operation, and the IPI 200 Series, which are standalone, IP-addressable modules. Above: Digital Acoustics’ IP7 Ethernet/IP intercoms and IP intercom products provide voice-quality audio over local area (LAN) and wide area networks (WAN) with minimal bandwidth utilization and network support for PoE and dual RJ45 connections. Why would a manager move intercom to the IP network? IP is densely distributed in most companies; every office is connected. Even utility closets and restrooms are within a few feet of the network. Intercom is audio transmission, including voice. So it’s a natural extension to voice over IP (VoIP). Since the standards are written and the deployment of VoIP is well established, few changes need to be made to introduce intercom and paging. IoIP will be applied in much the same manner as traditional analog intercom. Schools, hospitals, companies, airports, and retail outlets will likely embrace its use. However, it will have applications in homes and churches, also. Traditional intercom transmits audio signals from a central point to an outlet in analog form, usually over a pair of wires. The circuit is rarely shared with any other form of media. Paging systems use a similar method. However, intercom is point-to-point communications. A signal is sent in one direction and then a response is carried back. Paging sends a signal to many or all end-points and doesn’t provide for a response. Both methods are possible over IP networks, however, paging places different bandwidth demands on the network because a common physical infrastructure is being used. THE IOIP ARCHITECTURE Like most client-server data applications, intercom systems have a star architecture. A central control system, often located in an administrative office or security office, sets up calls, defines end-point functionality, emanates broadcasts, and generally coordinates activities. When an intercom conversations starts, the voice signal is wrapped in an Ethernet/IP/UDP packet, the same as in VoIP. Even the codec that digitizes the signal is most 32 | AV TECHNOLOGY | october 2008 www.avtechnologyonline.com http://www.avtechnologyonline.com

Table of Contents Feed for the Digital Edition of AV Technology - October 2008

AV Technology - October 2008 Contents Precedent Corporate: Residential AV Does Not Equal Commercial AV Government: Funding Problems? Education: DIY ISP.EDU, Part Two The Cost of Bandwidth Star Grounding Wars Understanding IoIP How to Equip a Smart Classroom Two Rooms With A View From Primitive to Professional Product Review:�Visionary Solutions AVN 420 Encoder Product Spotlight: Document Cameras New Products Ad Index AV MO: Using Infrared Microphones

AV Technology - October 2008

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