Switching to VoIP

This is the Title of the Book, eMatter Edition

Copyright © 2007 O’Reilly & Associates, Inc. All rights reserved.

Surveillance Systems and Videoconferencing

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point a stationary camera, zoom in and out, and so forth. More sophisticated cam-

eras add infrared night vision, multicast streaming, and other cool features.

To check out some surveillance cameras that are inadvertently avail-

able for your perusal on the Internet, trying Googling:

inurl:"ViewerFrame?Mode="

Video can eat up a lot of network bandwidth, 5 to 25 times that of a typical G.711

phone call, depending on the video codecs, resolution, and color depth employed.

Some developers, like DIVR Systems (http://www.divrsystems.com) offer remote

video surveillance solutions that ride on the same network as VoIP. In order to keep

from having video swamp the network and break down phone call quality, your

video surveillance apps need to play nice with QoS. This means making sure that

surveillance traffic is treated with a lower priority than phone call traffic.

Videoconferencing

Video meetings are closer to telephony than video surveillance, but their require-

ments are a bit different. First off, while video surveillance needs reliable delivery to

ensure that every frame of video is recorded, videoconferencing is more like a phone

call; if a frame gets dropped here and there, no problem. So reliable packet delivery,

a la TCP, isn’t necessary. ...