Aliso Viejo-based QLogic said Thursday afternoon that it has acquired NetXen, a maker of network interface cards (NIC). According to QLogic, it paid $21M in cash for the firm, which developers Fibre Channel over Ethernet (FcoE) adapters for the storage area networking market. NetXen was based in Cupertino, and was backed by Accel Partners, Benchmark Capital, DAG Ventures, and Integral Capital Partners.