SAN JOSE, Calif., Sept. 28 -- Cisco Systems Inc. has completed the acquisition of privately held Allegro Systems Inc. Cisco previously announced a definitive agreement to acquire Allegro Systems, a developer of virtual private network (VPN) acceleration technologies designed to enhance the performance and functionality of secure networking technologies. The acquisition strengthens Cisco's existing VPN and security solutions with added performance capabilities to meet the growing requirements of organizations connecting remote offices, employees and customers to corporate networks and the Internet. The acquisition of Allegro Systems is being accounted for as a purchase.