Sales of Internet security companies have also been rising as companies spend to protect their networks from threats such as the recent Mydoom worm that infected computers worldwide. Analysts said the deal broadens Juniper beyond network routers and other equipment and helps it sell to corporations, positioning it to better compete against San Jose-based Cisco. "It finally answers the question of how is Juniper going to grow beyond the carrier space," said David Willis, networking analyst for Meta Group. He does not own any Juniper shares. Analysts said NetScreen gives Juniper strong products in firewalls and VPN — or virtual-private-networking — technology used to guard networks from viruses, hackers and other Internet security threats. Many employees use VPNs to access corporate networks while away from the office.