Acme Packet, Inc. is engaged in providing session border controllers (SBCs) that enable service providers, enterprises, and contact centers to deliver interactive communications voice, video and other real-time multimedia sessions, across Internet Protocol network borders. The service providers include wireline, wireless, cable and Internet telephony service providers. The Net-Net products, which consist of the hardware and software, serve as a central element in unifying the separate Internet protocol (IP) networks. SBCs are deployed at the borders between IP networks, such as between two service providers or between a service provider and its enterprise, residential or mobile customers. The Net-Net products support a range of communications applications at multiple network border points, providing control functions in the areas of security. In April 2009, Acme Packet, Inc. acquired Covergence, Inc. 

http://www.acmepacket.com/