Voice over IP--the better choice.
Voice over IP (VoIP), or IP telephony, is a technology for transmitting voice "phone calls" over data networks using Internet protocol. IP telephony offers many benefits to consumers and businesses, including significant reductions in phone costs. VoIP, however, is not just about making free calls over the Internet. It is about a transformation of the traditional "circuit-switched" telephone network to a packet-based network that deploys voice-compression algorithms, and flexible and sophisticated transmission techniques delivering richer services using only a fraction of traditional digital telephony's usual bandwidth.
The migration to VoIP is still in the early stages. An IP telephony network is inherently more efficient than a circuit switched telephony network and improves capacity while lowering costs. Many enterprises, call-center operations and service providers--including ISPs and competitive local exchange carriers--are upgrading their networks to support interoperability between packet-switched and circuit-switched telecom options.
The reason that IP telephony technology is the better way for voice transmission, and thus a better choice for the enterprise telephony networks, has to do with the difference in how voice is transmitted with circuit-switched vs. packet-switched networks.
FROM CIRCUIT TO PACKET
Most contemporary voice networks and public-switched telephone networks are still largely circuit-switched. Common examples of switches include private branch exchanges (PBXs) and central office switches. These traditional circuit-switched platforms are not as efficient--nor as intelligent--as the new packet-switched alternatives.
Circuit-switched transmissions are tied to a standardized bandwidth rate for voice conversations and must maintain a highly synchronized timing of data being sent in each transmission. All the circuits and switches must make sure each digital piece of voice in a stream of voice chunks on the network travels and is received in exactly the same order and pace from starting point to the final destination. In order to maintain acceptable voice quality in this type of network, however, some of the available bandwidth is compromised in useless data and creates silence as part of the voice stream. When most people talk on the phone, each person takes a turn speaking. This means most speakers are only sending actual data (sound) in one active direction at a given time.
With IP telephony, voice becomes just another kind of data. The "data" is broken up into packets that flow independently across the network from the end point to the other end point. Computer-based algorithms detect pauses. The beginning and end of each pause is noted and compressed out of the data block. The voice stream itself is compressed down to as little as 5.3 kbps, compared with 64 kbps for uncompressed circuit-switched voice. The end result is far greater efficiency in the network.
With IP telephony, network management is also simplified. The development of IP telephony as a next-generation network makes that hope a true reality: a single network that supports a blend of voice, data, fax and video.
THE BENEFITS OF VOIP
IP telephony has just begun to enter the business world. Already, there are many benefits that it offers to the enterprise. First, most service providers and users still rely on a fixed-rate billing. This means cheap phone calls can be made over these packet-switched networks.
Second, enterprises are benefiting from VoIP in more managed IP networks and intranets. Here, packet delays and paths are more easily managed and controlled than through the ISPs. The business can put in a gateway to interface to an existing phone system or PBX, or replace a traditional device with an out-of-the-box IP PBX. With these types of deployments, enterprises can avoid traditional telecom toll charges on calls, and distribute centralized PBX services to users in multiple locations across the managed IP network
Another plus to the consolidation of voice and data network is a significant cost savings in network equipment and operations. Internet traffic is doubling every six to nine months. That means today's data networks function as overlays to voice networks that will soon carry the majority of the traffic. Enterprises will soon have to convert the underlying voice networks to a packet-switched architecture to handle this change in communications, and to a common switching and transmission system.
Within the next five years, most businesses will likely have to factor in at least some portion of voice over IP.
Snider is vice president of marketing and sales at Ericsson Enterprise Systems, Menlo Park, CA.
Circle 272 for more information from Ericsson
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|Comment:||Voice over IP (VoIP) technology uses packet switching instead of traditional circuit switching to transmit 'telephone calls' over data networks and offers such benefits as significant reductions in long-distance phone costs.|
|Date:||Oct 1, 2000|
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