When it comes to IP VPN services, what do you care most about? For Mitch Barlow, CTO of United Communications Group, the answer is easy: uptime.

In the five months since Barlow switched from private line services to a managed IP VPN service from AT&T, UCG has not experienced any downtime. And the one significant problem UCG has faced - a virus-infected laptop that was sending out so much traffic that it slowed overall network performance - was quickly identified and resolved.

"My top three priorities for our VPN services are uptime, having consistent speeds on the network, and having the ability to quickly isolate problems," Barlow says. He adds that so far he is happy with his decision to migrate off a private network to an AT&T service based on Multi-protocol Label Switching (MPLS) technology.

UCG is a Rockville, Md., provider of business publications, conferences and software. Growing rapidly through acquisition, UCG found that its point-to-point network built out of private circuits was unable to support new locations and applications in a cost-effective manner.

"We have a lot of communications between our Maine and Florida sites, and all of that had to come through Rockville," Barlow says. "It was getting too expensive and taking up too much time to have a hub-and-spoke network design. And it was getting hard for us to add new applications like video conferencing."

Last year, UCG decided to replace its network with an IP VPN. After talking with AT&T and Sprint, UCG chose AT&T as its ISP. 

Since October, AT&T has been providing UCG with MPLS-based services that link the company's headquarters in Maryland with offices in California, Florida, Maine, Massachusetts and New Jersey. A Washington state office will be added this spring.

UCG's 1,200 employees have access to the VPN, which carries e-mail and video conferencing. The VPN also supports key business applications including financial reporting, subscription processing and data replication.

"We have not gone to voice over IP yet," Barlow says. "We're experimenting with it in our Rockville office, and they've switched to VoIP for local traffic in our New Jersey and California offices."

UCG hasn't taken advantage of any of AT&T's managed security services such as personal firewall service or Internet Protect, which proactively seeks out viruses, worms and other Internet-based threats.