High-quality IP

Communications News, April, 1998

A virtual private IP video network provides savings and enhances quality for corporate users.

Though videoconferencing is far from ubiquitous, industry watchers estimate that more than a million people have participated in a corporate videoconference or watched a business video broadcast this year and left with a positive impression.

At networking giant Bay Networks, more than 500 people use video or corporate communications each day, according to Pierre Pellissier, Bay's network manager. The company uses video for scheduled and ad hoc meetings among remote teams, product and sales training, and a range of consultative calls where visual communications enhance the user experience.

Across the board, business managers are wondering how video communications will work profitably in their futures. New technologies must either cut or shift operating costs without affecting revenues, or produce new sources of revenues far greater than the investment costs of the new technology.

At first blush, real-time video communications technology seems expensive to own and operate. A room or small group videoconferencing system can cost between $4,000 and $40,000, depending on quality and functionality. And, like telephones, one isolated unit without a network is completely useless.

Until this year, the recurring costs of video transport services presented a very significant obstacle to deployment. When video and audio go over the carrier's circuit-switched infrastructure (ISDN line pulled to every video-ready room, or a T1 to the facility with multiplexing equipment on premise), the company can pay as much as $180 an hour (for a 384 Kbps call on ISDN originating in Pacific Bell territory and terminating in the Bell Atlantic region) for these services. This is the case when service used infrequently.

When video meetings exceed about 15 hours a month, company can justify leasing a T1 from the local carrier and usage rates drop somewhat.

Many businesses are using local T1 and E1 loop service heavily for their voice traffic and lightly for video, but they have to pay for the long distance tolls. In contrast, a virtual private network (VPN) permits companies to move off exclusive private networks and reduce costs.

The hitch in using a VPN is that calls will have to become protocol-specific, instead of just "digital dial tone" accessible from either the PBX (for voice), or the multiplexer for bonded video traffic.

First-tier network service providers (NSPs) like Concentric Network of Cupertino, Calif., have seized on the T1 as a means to give corporate customers access to high-quality IP environment, where the customer can save money by comparison to public switched services on both voice and video traffic.

Concentric Network's infrastructure and value-added services, created in partnership with videoconferencing leader PictureTel, offer flexibility, low-latency, security, reliability, and cost savings for companies which, like Bay Networks, see video communications becoming an integral part of their business processes.

A well-designed and conditioned advanced IP network like Concentric's backbone can carry data, voice, and video traffic equally well. From the point of access on the campus, the Concentric virtual private IP network is available for all the corporate users, from those on group videoconferencing equipment, such as PictureTel's Venue or Concorde Systems, down to the desktop users with any H.323-compliant protocol stack.

H.323, the ITU protocol that specifies how an IP network provides transport for all multimedia data types, supports voice over IP networks in addition to video. It is the basis for all emerging IP telephony and next-generation multimedia communication products. The standard is already widely accepted by companies developing networking equipment for intranets and the public Internet.

Products such as legacy group and room videoconferencing systems are generally not H.323 compliant. Rather, they adhere to an earlier standard for ISDN networks, the ITU H.320 standard.

Since there are more than 15,000 companies with standalone H.320-compliant videoconferencing in place today, users are likely to need a way to access the ISDN network on occasion. Concentric recommends these users install the RADVision VIU 323, an H.323-to-H.320 converter available from authorized resellers.

Cost savings come primarily from eliminating recurrent ISDN network usage costs and providing equivalent video network services with a lower-cost, more manageable and user-friendly IP infrastructure.

According to Dr. Michelle Blank, president of RADVision Inc., "Our VIU was designed to protect and extend an organization's investment in legacy systems. The VIU provides a `bridge' that connects such legacy systems as H.320-compliant videoconferencing room, rollabout or small group systems to H.323-based desktop conferencing networks. There is no need to install expensive ISDN lines to expand the network of interoperable endpoints for VIU-enabled conferencing systems."