April 18, 2001, 1:29 PM — In the rapidly evolving world of VPNs, some service providers are trying things that defy easy classification yet can be a good match for particular firms.
Conventional VPN service providers -- if you can use that term for such a young market -- manage equipment they set up at your sites and issue VPN clients to dial-up users. WorldCom, for instance, offers this style of service, and absent the outsourced management, this is similar to what you might do if you built your own VPN.
Other conventional service providers start the VPN within their network so the secure tunnels created by the VPN end at the provider's point of presence (POP), not at customer sites. Customer traffic runs over unsecured access links between POPs and customer sites. The argument for this model is that these links are secure enough.
Some upstarts offer VPN services based on other, less-conventional models. For instance, CoreExpress is building a backbone network and guarantees quality of service across it using its own network tied to the access networks of AT&T, Genuity, Sprint and UUNET.
At the moment, customers still have to install their own VPN gear at the ends of the connections, but they get guaranteed network performance because the traffic flows over CoreExpress' network, not the Internet. Within six months the company plans to offer VPN services through agreements with other vendors, according to Greg Davis, vice president of marketing.
CoreExpress leases fiber links from two carriers, Williams Communications and Level 3 Communications, and lights it up with Sycamore optical core switches that it feeds with Juniper edge routers and Cisco core routers. Customers must buy Internet access from one of the four ISPs. Before accepting a customer site and making service-level commitments, CoreExpress tests how fast traffic gets from customer sites to the CoreExpress edge routers. If it is not fast enough to support a maximum site-to-site delay of less than 150 msec, CoreExpress won't provide the service.
This service is attractive to Magellan Health Care, which manages mental health and substance abuse care for health plans, insurance companies and large employers. As Magellan gets new clients, it needs to tie them into the firm's network, generally within 60 days.
That's not enough time to get a frame relay connection, the firm's traditional way to connect sites. But it is enough to get a dial-up connection to one of the ISPs, says Bob Odenheimer, Magellan's senior vice president for IT, operations and telecommunications. Dual ISDN lines offer 256K bit/sec links to an ISP, he says, and the CoreExpress backbone gives the performance that customers need. "Our customers have certain expectations: They need faster-than-normal Internet response times, and they need consistent response times," Odenheimer says, adding that CoreExpress provides both.