LOWELL, Mass. — Convergent Networks Inc., one of the survivors in independent softswitch architectures, is moving full bore into cable-TV-based packet telephony, with the introduction of a new Cohesion family switch that meets CableLabs' Trunking Gateway Control Protocol standard. The system will use a highly dense line card based on Texas Instruments' voice-over-IP (VoIP) DSPs, which Convergent introduced a year ago as a telephone company-based product, but which Convergent now admits was developed all along with cable TV multi-system operators in mind.
Carl Baptiste, managing director of marketing at Convergent, said that the company had been promoting its media gateway for MSO Call Management Solutions for several quarters. However, Convergent was specifically attending CableLabs PacketCable meetings, participating in interoperability tests, and upgrading TGCP support, with the combined mission of developing an optimized solution for cable MSOs. A few MSOs are still expanding circuit-switch-based telephony for existing cable customers, but most are turning to VoIP packet telephony to pull voice call customers away from incumbent phone carriers.
"This has become strategic for many MSOs," Baptiste said. "Even with cable modem/digital TV subscription packages, they're losing business to the satellite TV providers in a big way. They have to add telephony to make their bundles compelling and profitable."
Convergent is bundling its Cohesion CMS media gateway with a Signaling System 7 gateway, a tandem proxy, and an element management system. In a combination of tests at Convergent headquarters and at CableLabs' Louisville, Colo. headquarters, Convergent has tested its switches with client phone systems from Motorola, Texas Instruments, Cisco Systems, Terayon, Arris, Scientific-Atlanta, and Thomson/RCA; with headend equipment from Cisco, Arris, and Motorola; and server software from Broadsoft, VocalData, and Sylantro. Next up is testing with gateway software from Gallery, Syndeo, Siemens, and Telcordia.
"We've pretty much covered the gamut of PacketCable providers," Baptiste said.
The "CohesionZone" architecture Convergent has designed for MSOs is centered on its ICS2000 voice gateway, upgraded with dense line cards, and with software support for TGCP and SIP (Session Initiation Protocol). An adjunct tandem proxy speaks CMS Signaling for tandem telephony applications, while a signaling gateway speaks SS7, for interface to standard circuit-switched phone systems.
The point in configuring with the densest line cards, Baptiste said, is that in one standard rack shelf, 24,192 IP calls can be supported. When three ICS2000 systems are populated in a seven-foot rack, 72,576 IP calls can be supported. The line card also supports redundant Gigabit Ethernet, so that systems based on Ethernet transport can handle IP telephony aggregation.
