If the shift to data includes a shift in the variety of services offered and in the terms by which they can be purchased, the whole service process could descend into chaos. A new view of how services are ordered, provisioned, and supported must be created to prevent this chaos. Switching, transport, and service were bound together in a single network. It's not surprising that the OSS process was likewise bound to the support of voice telephony. Provisioning, in voice services, means assigning wire pairs or timeslots.
Billing means recording call details and pricing the recorded calls.
Data services today are predominantly leased-line services. The problems arise in areas of virtual network services, such as frame relay, and it is these services that will account for most of the growth of telecommunications spending in the next decade. This QoS level represents the average experience of the users in peak traffic, average traffic rate, traffic delay, and the risk traffic will be discarded or lost. Service providers combine many users on a single network, fitting the peaks of one user's traffic into the low periods of another's. This makes more efficient use of facilities and permits lower service costs.