It seems that the makers of firewall\/VPN boxes agree that it is no longer enough to sell just firewall\/VPN appliances. Nokia this week announced an updated version of Internet Security Systems' RealSecure intrusion-detection software to go with its IP family of appliances.The integration of the two products makes it possible to identify intrusions and to automatically block some of them without human intervention.Meanwhile, Network Associates Inc. last week spent hundreds of millions of dollars buying up two companies, Intruvert and Intercept, to add to its security arsenal. That's a pretty good indication of just how important intrusion detection is in the mind of executives at NAI.The position of Watchguard, which makes firewall\/VPN appliances, is that small and midsized businesses don't have the resources to buy separate firewalls, VPN software and intrusion detection software, so learn how to set up each and manage them on separate management platforms.NetScreen is onboard with this theory as well. It expects that the stand-alone intrusion detection market over the next year will be pretty stagnant, and that businesses will buy multifunction security platforms.Cisco has been pushing some of its modular-switching platform as security devices to which you can add hardware modules. Each of those supports a separate security function.These are just a few examples, but the analyst firm the Yankee Group issued a report last week saying that security appliance vendors are doomed if they don't expand the security functions they support. And they include a broad spectrum of equipment vendors that need to broaden their scope, such as firewall\/VPN vendors and those that sell Secure Sockets Layer remote access gear. The mainstream business won't be buying limited function appliances in the future, Yankee predicts.If you buy into this theory, it might affect your procurement decisions now. Independent studies of these platforms are scheduled for later this year, and it might be worth waiting for them if you are thinking about buying such gear.