Following their success in improving data networking systems, Internet technology developers are tackling how the Internet can capably handle other forms of traffic, including voice and video communications. The emergence of services such as Internetbased telephony and video promises to enable sta
Following their success in improving data networking systems, Internet technology developers are tackling how the Internet can capably handle other forms of traffic, including voice and video communications. The emergence of services such as Internet-based telephony and video promises to enable state and local agencies to cut transmission costs, deliver desktop multimedia applications and combine previously autonomous data and voice networks.
Many telecommunications firms are convinced that Internet Protocol will be the standard transmission solution for most forms of communication. "Once users have a more powerful way to access the wide-area networks, companies can deploy more sophisticated applications, such as videoconferencing," said David Sokolic, a strategic marketing manager at VocalTec Communications Ltd., a Northvale, N.J., supplier of IP solutions.
Pricing also will be a draw because IP-borne traffic costs less than private and public switched network alternatives. "Customers can cut their telecommunications 30 percent to 40 percent by moving to IP telephony," said Jean Paul Deschamps, marketing manager for voice and data products at 3Com Corp.'s London office.
Rather than paying per-minute network usage charges, agencies might be able to sign up for services from Internet service providers (ISPs) that offer unlimited access.
Finally, network management might be simpler once a unified approach to handling various forms of traffic is adopted. "Right now, we have separate data and voice networks," said Richard Hack, the director of the Office of Systems and Telecommunications Management at the U.S. Commerce Department. "If we could merge them onto a common communications mechanism, that would greatly simplify our management functions."
But while such benefits are enticing, the infrastructure needed to support IP telephony and video is not quite robust enough for widespread use. The Internet was designed to carry data traffic, and it handles that task quite well, but voice communication is a new area for the Internet. When compared with telephone network equipment, which vendors have spent years honing, Internet switching equipment is unable to deliver the same voice clarity.
That is important because most agencies will not tolerate quality degradation. "While an individual making international calls may be willing to trade the lower level of quality that IP telephony offers for significant cost savings, government agencies will not," said Paul Stockford, an industry analyst with Cahners In-Stat Group, a Scottsdale, Ariz., market research firm.
Quality problems also stem from the fact that voice is more demanding than data. While a user will sit and wait for data to be downloaded to a PC, no such delays are expected during a conversation. On the Internet, slowdowns can be caused by many reasons, but congestion is the most common. The Internet parcels bandwidth on a first-come, first-served basis, so the number of users sending information and the amount of data transmitted constantly changes.
Mark Murray, the manager of product marketing for voice technologies at Cisco Systems Inc., San Jose, Calif., noted that voice compression techniques that enable carriers to squeeze more calls onto their networks also contribute to the problem. Compression adds another step to completing a transmission and could lead to network latency, which is dead transmission time that can become static on a line.
To eliminate delays, ISPs need to add to their networks quality of service (QOS) features, which allocate bandwidth for specific applications so that they are not affected by other transmissions.
While network equipment suppliers and ISPs would like to add this capability throughout the Internet, they first have to rally around common standards. Currently, two techniques have emerged as possible solutions: Asynchronous Transfer Mode QOS, which works well on wide-area networks, and Reservation Protocol, which is designed to operate on local-area networks running Transmission Control Protocol/Internet Protocol.
Neither approach has gained significant market share, so it is too early to determine which will become the de facto standard. However, carriers can add QOS features to their own networks and ensure high quality for calls that travel on those networks.
Equipment scalability is another roadblock for IP telephony. "The first few rounds of IP telephony equipment were built on PCs running Windows NT; recently, vendors [have been] starting to deliver more scalable Unix systems," said Mordy Rothberg, executive vice president at IDT Corp., a Hackensack, N.J., IP telephony supplier.
Initial products supported hundreds of ports, which was fine for corporate networks but not for telephone networks, and now vendors have started to deliver switches that work with thousands of IP telephony connections.
In addition to lower voice quality, IP telephony users will have to give up some currently available enhanced network services, such as call waiting, conference calling and voice messaging, because the Internet lacks the underlying infrastructure necessary to support such services. Fixing this problem requires a gargantuan upgrade. Enhancements have to be to made to LANs, PBXs, customer premise equipment, Internet switches and central office equipment.
Because there are so many missing pieces, established ISPs have been holding back from offering IP telephony services. But a few small, start-up carriers have installed gateways that enable them to roll out services in select areas, identify calls going to other places and route those calls via the public network to their destination. These suppliers include Delta Three Inc., New York; IDT; LATIC Communications Corp., Rockville, Md.; VIP Calling Inc., Burlington, Mass.; and USA Global Link Inc., Fairfield, Iowa.
The services of these companies do not include one of IP telephony's biggest potential draws: free voice calls. Because parts of most conversations take place on the public network, these carriers bill their services in the same manner (per minute) as traditional telephone companies. But because their infrastructure is more modern, ISPs offer lower rates than established telephone companies.
Faxing is another popular application. Here, an agency can take advantage of potential savings while avoiding the problems that voice communications can suffer due to delays. Also, faxing does not make use of any enhanced services available on the public network.
Even with all the roadblocks, most experts agree that it is only a matter of time before IP telephony will be a regular service option for most users. Cahners In-Stat's Stockford said, "Because there is so much competition, the IP telephony market is evolving in dog years: seven years of progress in one calendar year."
Paul Korzeniowski is a free-lance writer in Sudbury, Mass., who specializes in computer issues. He can be reached at email@example.com.