Patent ID: 6169724
Filing Date: 2001-01-02
Classification: G06F,H04M,H04Q

Abstract:
A system for recognizing a call failure related problem occurring at an egress network of a telephone system, comprising: a terminating switch; an out-of-band signaling system for providing information relating to call failures occurring at said egress network; a loop around trunk coupled to said terminating switch for sampling a predetermined percentage of calls at said egress network; a protocol analyzer coupled to said loop around trunk for monitoring said information relating to call failures associated with said predetermined percentage of calls; and a host computer coupled to said protocol analyzer for calculating a measured call failure rate based on said monitored information relating to call failures, comparing said measured call failure rate to a threshold, and recognizing when said measured call failure rate exceeds said threshold; wherein a tolerable call failure rate is calculated by sampling a plurality of calls at said egress network and monitoring said information relating to call failures associated with said plurality of calls and wherein said threshold is calculated based on said tolerable call failure rate and a standard deviation associated with said calculation of said tolerable call failure rate.