Moving ISDN-Based Videoconferencing Onto The IP Network

摘要

Videoconferencing over IP has had potential for many years. Finally, the installed base of ISDN users is considering a move. Driven by cost, efficiency and quality concerns, the installed base of ISDN (H.320) videoconferencing users is moving to IP (H.323). Often this comes as part of a broader consolidation of circuit-switched traffic onto IP packet backbones (see "CalVIP Learns New QOS Rules"). This article briefly explains why this move is afoot, and discusses factors that contribute to a successful transition. First of all, corporate decision-making in the post bubble telecom world is driven primarily by cost. ISDN-based videoconferencing is a visible and useful service in most large corporations, but it can be expensive. ISDN BRI and PRI lines cost roughly $30 per month, whether they are used or not, and usage charges run about 20 cents per minute. Each ISDN videoconferencing room or office needs three BRIs (for a 384-kbps call), and most calls are an hour to an hour and a half long. This means 60 cents X 75 minutes = $45 for the call, and a flat $90 per month to maintain the room. For an active videoconferencing environment, the per-call costs add up quickly, especially when users are calling overseas.