Code of Federal Regulations Title 47. Telecommunication § 47.4.7 Definitions of metrics used to determine the general outage-reporting threshold criteria

(a) Administrative numbers are defined as the telephone numbers used by communications providers to perform internal administrative or operational functions necessary to maintain reasonable quality of service standards.

(b) Assigned numbers are defined as the telephone numbers working in the Public Switched Telephone Network under an agreement such as a contract or tariff at the request of specific end users or customers for their use. This excludes numbers that are not yet working but have a service order pending.

(c) Assigned telephone number minutes are defined as the mathematical result of multiplying the duration of an outage, expressed in minutes, by the sum of the number of assigned numbers (defined in paragraph (b) of this section) potentially affected by the outage and the number of administrative numbers (defined in paragraph (a) of this section) potentially affected by the outage. “Assigned telephone number minutes” can alternatively be calculated as the mathematical result of multiplying the duration of an outage, expressed in minutes, by the number of working telephone numbers potentially affected by the outage, where working telephone numbers are defined as the telephone numbers, including DID numbers, working immediately prior to the outage.

(d) Optical Carrier 3 (OC3) minutes are defined as the mathematical result of multiplying the duration of an outage, expressed in minutes, by the number of previously operating OC3 circuits or their equivalents that were affected by the outage.

(e) User minutes are defined as:

(f) Working telephone numbers are defined to be the sum of all telephone numbers that can originate, or terminate telecommunications. This includes, for example, all working telephone numbers on the customer's side of a PBX, or Centrex, or similar arrangement.