BridgePort Networks, a start-up headquartered in Chicago with an R&D facility in Cambridge, Massachusetts, announced $13 million in nre venture financing by its current investors. The new financing brings the total capital raised by the company to $51 million.BridgePort Networks offers a software-based Network Convergence Gateway (NCG) that enables the convergence of mobile and IP voice and data services. The company has signed a global reseller agreement with Siemens Communications. Existing investors TD Capital Ventures, Polaris Venture...