A major focus for Qwest Communications in 2004 will be improving the reliability of its nationwide IP network, company officials say."We're going to continue to see our business customers putting mission-critical applications on IP networks. Whatever IP network they put them on - whether public or private - they're expecting carriers to get closer towards the elusive five nines of reliability," says Martin Capurro, senior director of global data and IP product management for Qwest.Last year, Qwest deployed across its IP backbone a service from Arbor Networks that serves as an early indicator of distributed denial-of-service attacks. The Arbor service also detects such anomalies as worms, routing instability and peering problems.This year, Qwest has an effort underway to better protect its core IP network infrastructure from hackers. Part of that effort involves making Qwest's network less transparent to the outside world."We have a significant effort within the company to take the publicly visible network and make it more resilient and less visible," Capurro says. "We're trying to make our entire core IP network infrastructure invisible to the public domain...There's really no reason to have aspects of our private IP network visible to the public."From a technology standpoint, Qwest claims to be the first carrier to take advantage of a reliability-oriented technique called Multi-protocol Label Switching Fast Reroute. Most top-tier ISPs support MPLS, a standard that provides different classes of service for network applications such as voice, data and video. With MPLS Fast Reroute, the self-healing capability in Qwest's network is based at the third layer of the IP rather than being based on the older SONET technology."We were the first carrier that implemented MPLS Fast Reroute," Capurro says, adding that all of Qwest's core routers are from Juniper. "We worked with Juniper on that, and we pioneered that in 2001."Qwest officials say that by continuing to improve the reliability and resilience of their IP backbone, they'll be better able to attract corporate network managers who are looking to outsource more network services to reduce their costs."If customers can buy a finished [network] service and we can provide the assurance, the visibility and the end-to-end SLAs, they'll probably more willing to let go and do it in a cheaper way," Capurro says.Having an ultra-reliable IP network also is key as Qwest transitions into providing VoIP services. In December, Qwest began offering VoIP services to residents of Minneapolis and St. Paul, Minn.