Outsourcing is a good hedge against changing VPN technologies and avoidin g the relatively high cost of owning equipment, training, u pgrading and maintaining. Service providers, such as BBN Planet and CompuServe, provide connectivity from the point of presence (POP) to the customer premises equipment (CPE), so you won't have to be involved in day-to-day administration of the VPN. You usually can choose how much of the management you want to outsource; for instance, you might want to outsource just the infrastructure while maintaining control over user authentication and access.

Not only are service providers offering tunneling, but they claim to improve data security. They say VPN traffic between your sites will travel only across the private network that they protect from the Internet. This may decrease the likelihood of an attack, but users within the service provider's networks may have access to your data as it travels from point to point. Everyday traffic is probably safe enough this way, but strategic plans and financials may need more security than the service provider can provide. At that point, you will have to think about alt ernatives, such as augmenting your tunneling with other encryption methods.

Some service providers are partnering with security vendors to offer necessary value-added services to their customers. VPNet has partnered with Pilot Network Services to provide the Secure Road Warrior Service, which lets users establish a client-based VPN connection to VPNet products managed by Pilot.

Finally, look for a service provider with extensive, possibly international, networks because larger service providers can offer better guarantees for quality of service (QoS) and network reliability over their internal networks than you will find on the Internet. And if your service provider covers a broad geographical base, you should also get adequate coverage of local POPs for road warriors.