MCI is beefing up service-level agreements for its Managed Network Service customers with guarantees that relate directly to individual networks as well as the carrier's backbone.

MCI has changed its mean time to repair (MTTR) guarantee to a time to repair (TTR) guarantee of three-and-a-half hours, and it has changed its network availability guarantee to a site availability guarantee.

MCI has made "significant changes" to its SLAs, says Steven Harris, a research manager at IDC. "Carriers use mean time to repair as an average for all customers over the month. Your network could be down much longer, but if the average for all customers falls [under the SLA] you get no credit."

If MCI misses its TTR SLA users receive a credit of 5% of their monthly reoccurring charge.

MCI's TTR SLA is ahead of those offered by competitors. AT&T is offering its managed data service customers a four-hour MTTR SLA. Sprint offers a four-hour TTR guarantee for its managed service customers.

MCI also has improved its network availability SLA. Managed Network Service customers with dual routers and dual circuits and those with ISDN, DSL or dial-up backup were offered a 99.9% network availability guarantee. MCI now is offering a 100% site availability SLA for users with dual routers and circuits. The carrier is offering a 99.95% site availability guarantee for customers with ISDN, DSL or dial-up backup.

Similar to MCI's TTR change, the carrier's site availability guarantee also offers users a more tangible SLA that applies directly to their network, Harris says. Network availability SLAs guarantee that, on average, a carrier's network is available to all customers a certain percentage of time over a one-month span. The SLA is not specific to each customer connection. MCI now guarantees that each endpoint on a customer's network can access MCI's backbone.

The carrier is now also offering a four-hour TTR guarantee for third-party network connectivity. The guarantee only applies to third-party network connectivity from 10 service providers: AT&T, Sprint, Verizon, SBC, BellSouth, Qwest, NTT, Equant, BT and Deutsche Telekom. MCI says it is regularly reviewing the list and might add carriers.

MCI also is now offering its global Managed Network Service customers a four-hour TTR guarantee for users in 21 countries outside the U.S.