A network service in which the contractor provides not only the basic bearer mechanisms between access points, but also a range of management activities, typically those ensuring that the end-user will receive an agreed level of service measured in terms of availability, recovery from breakdowns, traffic levels, response times, and so on. Much of the necessary equipment and services can meet the needs of a number of different clients that are based in the same or in overlapping geographical areas, so reducing the total cost of the contractor’s operation. The advantage to the user of an MDNS is that the responsibility of providing standby facilities and trained maintenance are delegated to the provider of the MDNS, which should offset the user’s loss of flexibility.