Customers say that for true high availability, they want a provider that owns its own fiber (or other cabling) and infrastructure equipment, and can offer fully redundant components and paths.For this reason, the government of Westchester County, N.Y., has long used optical services for voice, video and data from Lightpath, a carrier serving the Northeast, to connect about 200 locations dispersed across a 500-mile area."If there's a big public emergency, we're the one agency that has to operate," says Norman Jacknis, the county's CIO. "We require dual-entrance paths at all major locations, such as the county seat and emergency operations center in White Plains, the health department in New Rochelle, the police and fire departments and the airport."When you get down to it, not all carriers are able or willing to provide that, Jacknis says. Westchester County's original RFP\/RFI went to nearly 100 carriers and equipment vendors (the county was open to building its own network).Under the covers, Jacknis says, many carrier network designs are dependent on central service points that can become single points of failure. "Other carriers just don't have the capital resources to do [a diverse network design] right," he says.\u00a0A couple big-name bidders wanted to resell part of the network from the incumbent local exchange carrier. This meant that the primary provider couldn't offer network guarantees end to end, which didn't sit well with Jacknis.Ditto for Dan Spinosa, director of enterprise communications technology at New York's North Shore-Long Island Jewish Health System, a 50-site Lightpath shop.\u00a0"Reality says that if there's another provider in the middle and we're not their customer, [service and support] break down," he says.Lightpath, Spinosa says, "will roll in UPSs, generators and technicians, even if a problem is not their issue [such as an electrical outage]."Spinosa noted that there were some downtown New York locations where Lightpath had to use the incumbent local carrier to complete last mile, but service degraded.\u00a0 "So Lighpath got landlord approval to create an alternate route to bypass that last mile using fixed wireless services from a building in the middle," Spinosa says.Jacknis chimes in that his Lightpath network service worked during the recent East Coast blackout and held up in the 9\/11 aftermath."You can't anticipate all of what might happen, so you must have diversity," Jacknis says. "There's no such thing as a safe place."