They advise network managers to wait at least another year before they consider major infrastructure changes involving VPNs. Today potential users h ave to contend with different approaches to VPNs. The technology has been used in firewalls, remote-access servers, gateways, routers, dedicated hardware, specialized server software, and even clients. So although industry promoters express certainty that 1998 will be the year when VPNs take off, here in 1997 longstanding problems remain unresolved. As before, different VPN products are largely incompatible with one another.
Standards are closer to completion but still developing.
Although there are various methods for deploying VPNs, few have actually been installed. Therefore, there is little real VPN experience in the IS community from which network managers can learn. By next year, however, standards could finally have coalesced, and prestandard interoperability, which is being demonstrated now, may appear in more products. Yet these prospects are not enough to satisfy some doubters. It's not a mainstream technology, and I don't think it ever will be.