scope:

This TR enhances and replaces the work of TR No. 38 [3].

Purpose

This Technical Report (TR) provides methods (guidelines and algorithms) to the telecommunications industry and users for analyzing CC Docket 91-273 [1,2] service outage data that is reported to the Federal Communications Commission (FCC). The industry is expected to use these methods to better analyze network outages. In particular, this TR provides a response to a Network Reliability Steering Committee (NRSC) request for input to its quarterly and annual reports to the FCC and the telecommunications industry. The NRSC is a committee of the Alliance for Telecommunications Industry Solutions (ATIS) with the mission to ensure a continued high level of network reliability.

Application

This TR will enable the telecommunications industry and users to evaluate the reliability and quality of services in telecommunications networks.

Outline

Section 2 reviews related work. Section 3 is the introduction to this TR. Section 4 describes general, desirable properties of an outage index. Section 5 defines the outage index recommended in this TR, by specifying the FCC and NRSC data used as well as the algorithms for calculating the outage index. Section 6 gives three detailed outage examples of how to apply the algorithms given in Section 5 (for local switch, tandem switch, and facilities failure cases). Sections 7 and 8 discuss calculation of an aggregate index for multiple outages and application to FCC-reportable service outage data. Section 9 suggests areas for future work, and Section 10 gives a summary. Sections 11, 12, and 13 provide definitions, acronyms, and a bibliography, respectively. Appendix A provides two techniques for analyzing the number of outages in a time period, based on FCC-reportable service outage data. Appendix B gives additional examples of outage index calculations. Appendix C provides procedures for calculating the outage index in cases of gradual restoration of service(s). Appendix D furnishes equations for estimating confidence intervals for aggregated outage index values. Appendix E gives processes to normalize the outage index for differences in time periods.