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Proxilliant’s DIB Reduces VoIP IngressProxilliant Systems Corp. is showcasing the North American debut of its Dynamic Ingress Blocking (DIB) technology. By TED GLANZER, TMCnet Communications and Broadband Columnist Numerous practical and technological issues face MSOs to deliver quality and reliable telephony service through Voice over Internet Protocol (VoIP). On the practical side, the availability of 911 comes to mind. An example of a technological VoIP gremlin is ingress noise. To explain briefly, VoIP is comprised of several interconnected processes that convert a voice signal into a stream of digital packets on a network, which is then converted back. Ingress noise causes the losses of a large number of these packets, resulting in poor call quality and/or call drops. Consumers certainly will not tolerate such service, no matter how much money they are saving through triple play bundling. Enter Proxilliant Systems Corp., a company based in Stockholm and Bala Cynwyd, Pa., which is showcasing the North American debut of its Dynamic Ingress Blocking (DIB) technology at SCTE’s Cable-Tec Expo 2005 in San Antonio on June 14-17. According to a statement, DIB is designed to reduce ingress in cable networks, thereby providing MSOs the opportunity to deliver VoIP services more effectively. “VoIP services are extremely sensitive to packet loss as packet loss deteriorates the quality of the voice service and cause call drops,” Arne Ljungdahl, CEO of Proxilliant, said. “Ingress in the cable return channel is the Achilles heel of cable networks, as ingress generates too much packet loss for VoIP. DIB effectively confines the ingress very close to the origin so that it does not jeopardize VoIP. Rather than running a never-ending campaign against ingress, this technology deals effectively with the issue.” According to the statement, DIB technology works by broadening the pipe for two-way traffic in cable networks; noise is blocked by disabling the return path between transmissions and cutting off the effects of ingress noise. The principle behind DIB, according to the statement, is that the subscriber return path is only opened during the short period that data is being transmitted from the home. DIB continuously monitors these signals in the return path and only opens the path when valid data comes from the home. The channel closes when the return data burst ends. By reducing the number of simultaneously open return channels, DIB blocks ingress noise and reduces total noise levels. DIB, according to the statement, eliminates node splitting in cable networks and “greatly improves capacity and service quality and saves significant resources from the cumbersome daily task of hunting and fighting ingress.” In related news, Proxilliant on May 25 announced that it acquired funding from venture capital firms Northzone Ventures and Creandum to expand globally. ----- Ted Glanzer is assistant editor for TMCnet. For more articles by Ted Glanzer, please visit: http://www.tmcnet.com/tmcnet/columnists/columnist.aspx?id=100033&nm=Ted%20Gl anzer |