San Jose-based Cisco said last night that it has signed a definitive agreement to acquire the set-top box business of Chinese firm DVN (Holdings Limited. DVN developing digital cable products, and is listed in Hong Kong with operations in China. Cisco said it will pay $44.5M for the set-top box business of DVM, structured as $17.5M in an upfront payment plus $27M paid over four years based on sales milestones. Cisco said it will also tie with DVN in a go-to-market appliance. DVN's hardware is used in the Chinese cable market.