For example, Cisco's AS5300 Access Concentrator is bundled with voice cards, Lucent sells the Ascend Max and TNT bundled with voice cards and 3Com bundles its Total Control Hub with voice cards. Service providers deploy VOIP concentrators as an alternative switching element to a Class 4 CO in delivering long distance phone service. With a prepaid calling card, a user dials an access number, which connects the user to a VOIP gateway instead of a traditional Class 4 switch. From there, the call is routed over a packet infrastructure, bypassing the traditional IXC long-distance network. This sets up a connection to a VOIP gateway, which then routes the call over an IP infrastructure bypassing the traditional long distance network.
Soft switches provide functions such as call control and routing.
The combination of VOIP, media gateways and soft switches represents a new way of thinking about the public network. For example, Sonus Networks and Salix Networks, started shipping next-generation platforms in Q4. Global Crossing has deployed Sonus gear in Detroit, Dallas and Rochester, and it will deploy in 20 more cities by August. The key difference between VOIP concentrators and the Sonus GSX 9000 Open Services Switch is density. The Sonus product can scale to 50,000 simultaneous voice calls, while VOIP concentrators max out at less than 5,000 ports.