Video over IP emerged as an alternative to ISDN-based videoconferencing.
IP-based videoconferencing is coming on strong as a successor to ISDN-based systems for cost-effective, application-rich corporate video conferencing.
Videoconferencing has always had the potential to save your company money and improve productivity by linking virtual teams in a high-impact communication and collaboration environment, regardless of geography. But the technology, typically based on ISDN connections over the public switched telephone network (PSTN), has been hampered by poor quality, implementation problems and high costs.However, several factors are coming together to kick-start IP-based videoconferencing:
- Most standard video conferencing products today are designed to accommodate ISDN and IP implementations.
- Vendors are starting to offer IP-based videoconferencing services.
- Many enterprises are already preparing their networks for voice over IP, which also provides the infrastructure upon which to add video.
- Companies are becoming more interested in video-based applications such as the multicasting of corporate events and training sessions, video-based collaboration among employees in different places and making video-on-demand available to employees.
- Vendors are beginning to offer IP-based packages that include straight videoconferencing as well as streaming video options.
If you’re considering a videoconferencing application and are debating whether to go with an IP or an ISDN implementation, here are the issues you need to think about:
Because most current videoconferencing systems support ISDN and IP, the investment in endpoint technology is the same. When it comes to transport costs, ISDN varies widely in different regions of the U.S. In some locations, flat-rate, all-you-can-eat ISDN services are offered, but in other cases you may have to pay a per-minute usage cost. By contrast, there’s no separate per-minute cost for IP because it runs over your IP-based data network or over a flat-fee service such as a virtual private network (VPN). However, the IP approach will likely require network upgrades to provide the bandwidth necessary for high-quality video.”I wouldn’t call the cost comparison a no-brainer,” says Andrew Davis, managing partner of Wainhouse Research. “If you go with ISDN, you have known costs. You pay by the minute. You have known technology, but you are doomed to live with an unreliable technology. You are committing to a system divorced from the rest of your enterprise.”Davis adds that with IP, “You have to beef up your network and beef up your support team. You’ll save money on ISDN, but you’ll spend it on more infrastructure and network support.” However, IP does provide a converged network of voice, data and video that is more logical and efficient for the long term. With IP videoconferencing people are encourage to use it, because the cost per call goes down the more you speak.”
2. Quality-of-service questions
When you talk about implementing video conferencing over IP, the first issue that arises is the lack of guaranteed quality of service (QoS).While a company can deploy and control QoS on its own LAN, the problem is sending video from one LAN to another LAN that may not support QoS. Because there are no end-to-end QoS standards yet, analysts recommend using one network vendor rather than mixing and matching.The other approach, of course, is to simply add bandwidth. The U.S. Census Bureau is using 50 Polycom systems running over IP at 768K bit/sec. Most of the units are spread around small conference rooms at headquarter buildings in Maryland, but about 15 are at the bureau’s National Processing Center in Jefferson-ville, Ind.”Our managers use videoconferencing to talk about how to change procedures, the status of data capture and the status of census activity in the field,” says Larry Patin, chief of the Census Bureau’s telecommunications office.Patin says his team is deploying Cisco routers to provide a 1G bit/sec backbone. That’s enough bandwidth to eliminate any traffic problems.
If you already have an ISDN implementation and you’re thinking of transitioning to IP, you’ll need to think about gateways.Typically, IP videoconferencing uses the H.323 international standard. Most current implementations include gateways into the H.320 ISDN-oriented PSTN. This allows companies to use IP for video calls within the enterprise and ISDN over the PSTN for calls to branch offices and other companies. This is an important capability because many companies are using legacy videoconferencing systems that support only ISDN. Also, without end-to-end QoS standards there are problems videoconferencing LAN to LAN over IP.So a firm that deploys IP videoconferencing often needs a gateway to communicate with customers, suppliers, business partners and others who are using ISDN. This gateway approach requires hardware supplied by vendors such as Cisco and RADVision to translate between the H.323 packet-switched and H.320 circuit-switched worlds.For example, the Census Bureau is using Cisco multipoint control units and Cisco gateways that translate between the H.323 and H.320 protocols.Another solution is to use a VPN that provides gateway services.
IP provides convergence of all multimedia, including one-way streaming, over the same network. In contrast, many ISDN-oriented videoconferencing systems are islands of technology that fail to integrate other applications.For example, Anderson at Prudential Select Brokerage started with ISDN-based videoconferencing as a way to link sales associates at field offices with headquarters for training in complex products, Internal Revenue Service regulations and legal developments. He also wanted to use videoconferencing for system-design sessions for the IS staff.Anderson chose Polycom as the vendor, primarily because Polycom ViewStation products offer integrated videoconferencing and one-way streaming video. “We got into this with Polycom on the ISDN point-to-point front, but it has quickly moved into an IP implementation,” Anderson says. Prudential Select Brokerage is deploying IP videoconferencing at 175 field offices throughout the U.S.Credit Suisse First Boston (CSFB) is upgrading its network to support a variety of IP-based video applications, including streaming video, video on demand and videoconferencing, says Ira Weinstein, global department head of media services.CSFB has been using videoconferencing for the past five years for analyst briefings, management meetings, corporate presentations and job interviews. The company holds an average of 30 room-to-room video conferences per day.Weinstein says he expects that IP will allow CSFB to extend videoconferencing to individual end users. “We’re looking for desktop videoconferencing to keep people at their core work locations doing business. When they get up from their desks for conferences and meetings, we’re losing money,” he says.
While legacy PSTN-oriented videoconferencing systems will continue as the main workhorses of visual communications over the next year, IP videoconferencing is gaining momentum. There are pros and cons to each approach.Based on his experience at the Census Bureau, Patin says, “The biggest problem with IP is network design and what you’ve got in place. If you have bottlenecks or traffic problems, IP videoconferencing will not work.”Prudential Select Brokerage’s Anderson says a key benefit of deploying IP videoconferencing is avoiding the provisioning and reliability issues of ISDN. These include installation delays and losing the connection in the middle of a call. “The telephone company issue alone has been frustrating for us and so has the cost,” Anderson says.Many IT executives are looking at IP videoconferencing products. As they plan network upgrades, video is increasingly a consideration. The promise of less expensive, more efficient video traffic over IP will make videoconferencing more viable enterprise wide.