Starent Networks has closed a $25 million fourth round of financing that will enable the manufacturer of mobile gateway devices to fund sales efforts from new offices in London and Tokyo, according to a story in the Boston Globe.

With the latest round, Starent has raised $80 million to date, which "is more than what we think we need to get to cash break-even,” according to President and CEO Ashraf Dahod. Starent’s gateway devices are designed to let wireless carriers charge different rates for different services, such as video messaging and push-to-talk features, the story states.

The company’s customers include China Unicom, South Korea's SK Telecom, Verizon Wireless's 300,000-subscriber Puerto Rico unit, and a Spanish-Portuguese venture called Vivo that has more than 17 million subscribers in Brazil.