From Ezilon.com
VoIP Dials Up Data Networks
By Ezilon.com Articles
Jan 24, 2006, 20:38
VoIP Dials Up Data Networks
In a traditional PSTN circuit, resources are dedicated to each direction of the phone call, regardless of whether anyone is talking. This inefficiency is exacerbated by the increasing percentage of data traffic tying up network bandwidth for longer periods of time. Equipment use improves substantially with a shift to a packet-based network in which shared network resources are consumed only when someone is talking.
This trend is far more fact than conjecture, as all of the big national and international telecommunications carriers have announced their intention to shift voice traffic onto data networks to improve the efficiency of both voice and data services.
However, there are several technical obstacles that must be overcome before this gain can be realized. The most significant is call quality. Call quality requires that incoming voice/data packets are correctly ordered, line echo is cancelled, and periods of silence are detected-all functions handled by DSPs.
A DSP-based Voice-over-IP (VoIP) system or gateway makes a shift to data networks possible, serving as the bridge between the PSTN and the packet network. VoIP gateways enable users to speak on regular phones or send information over regular fax machines as they bypass PSTN toll charges with no perceivable loss of quality.
A VoIP gateway is required at both the call's origination point and its destination, and often coexists with private branch exchange (PBX) systems within corporations that use VoIP. This allows interoffice voice and fax traffic from existing equipment to be carried on the firm's WAN or intranet. In addition, Internet service providers and other data- network owners are using VoIP gateways to offer telephone service over their networks at reduced rates.
But it doesn't stop there. DSP advancements in processing horsepower, smaller-footprint packaging, and reductions in power dissipation have dramatically expanded the number of channels carried on VoIP gateways and embedded in network backbones.
These significant DSP advancements are transforming a technology that was once used primarily to obtain free phone calls via a PC and the public Internet.
At the core of the voice and data-network infrastructure, DSPs are lowering the cost and increasing the quality of IP telephony. As a result, growing numbers of corporations and telephone service providers are realizing system efficiencies and lower calling costs by shifting voice traffic from traditional telephone networks over to well-managed, IP-based private data networks.
Next-generation telephone carriers such as Qwest and Level 3, with their extensive IP-based data networks, already are offering long-distance IP telephony services at significant savings to business and residential users. Studies show that paybacks from these IP telephony investments may be achieved in as little as six months.
A surprising number of companies are shipping products incorporating DSP- based VoIP products. These products include stand-alone VoIP gateways, in addition to those embedded in PBX systems, telecom switches, network routers, dial-up modem pools, cable modems, and telephones able to connect directly to a data network.
Most observers believe that the long-term driver of IP telephony will not be the short-term savings offered by reduced telephone costs. Rather, the driver will be those applications that utilize integrated voice and data traffic to improve productivity for everyone.
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