Cablevision (NYSE:CVC) announced that Optimum Voice SIP Trunking is now certified with the Cisco (NASDAQ:CSCO) Unified Communications 300 Series for small businesses. The pre-certified solution is designed to deliver voice service for small businesses that want to take advantage of an IP PBX system while avoiding the costs of an analog gateway or traditional T-1 solution. Cisco equipment that has received interoperability certification for Optimum Voice SIP Trunking now includes Cisco UC320 as well as the Cisco UC500 series PBXs.