An executive at VPN vendor SonicWall recently boasted that his company's purchase of low-end SSL VPN vendor enKoo gave SonicWall an attractive, inexpensive device that will rival the iPod in popularity.The company's Vice President of Sales John DiLullo also said the company plans more acquisitions in other areas including unified threat management devices - which are blending with VPN gear - but also backup and recovery gear and content management.This diversification is telling about more than just the fortunes of Sonic Wall. It is concrete evidence that the days of stand-alone VPN makers are done. With commodity vendors like D-Link selling firewall\/VPN appliances for small businesses and major networking vendors like Cisco, Nortel and Juniper including VPN as a single feature on broader security devices, there are few crumbs left for the pure VPN vendor to survive on.Most of the scores of VPN pioneers that cropped up less than 10 years ago have been either bought by larger companies, diversified like SonicWall, or folded. This consolidation is all part of a predictable business cycle that is now culminating in mature VPN technology.This is good for potential buyers of VPN technology no matter what their size. A small business can be happy that it can buy inexpensive, simple-to-use VPN equipment. And larger businesses can be glad that a single device under a single management platform can handle multiple security functions rather than many individual devices that add to administrative load.