Analysis of two trunk congestion relief schemes

During natural disasters such as earthquakes and hurricanes, call volume in the public switched network (PSN) often increases to levels that cause trunk overloads in switches. The result of this overload is an overall degradation in the grade-of-service of the PSN. At times like these it is vitally important that local, state, and federal officials be able to communicate in a reliable and timely manner so that the business of caring and providing for the emergency needs of people is unhampered. To combat the degrading effects of large call volumes, various priority controls have been developed to alleviate trunk overload for critical or select users. This paper describes two trunk congestion relief schemes and the results of a detailed analysis that quantified the performance characteristics and the availability of these schemes in the PSN.<>