Telecommunications network operations systems: experiences in software reliability engineering

Describes our practical experiences in applying software reliability engineering (SRE) technology to telecommunications network operations systems. These are real-time, high-availability systems used to provision, maintain and restore AT&T´s backbone telecommunications transport network. In this paper, we describe how we used SRE to ensure the quality and high reliability of three such systems prior to production. Key steps in applying SRE are: deriving an operational profile, developing a simulator test environment, and executing load, stress and stability tests. To reduce test intervals and increase system reliability, we apply accelerated testing and experimental design. In addition, our SRE program also incorporates customer-focused techniques such as operational scenario testing