Issues, Analysis, and Tools for Rural Call Completion Issues

The wireline telephone network has undergone significant changes over the past decade. This includes the introduction of new technologies such as SIP and the gradual reduction of wireline subscribers. One result is higher reports of issues connecting calls to rural areas than there were ten years ago. This issue is known as Rural Call Completion. Legacy network performance metrics, such as Answer/Seizure Ratio (ASR), or the number of answered calls divided by call attempts, seem incapable of identifying these previously unseen or unreported problems. Moreover, carriers typically calculate ASR on a weekly, monthly, or quarterly basis, meaning problems are long gone by the time they are detected. The Federal Communications Commission (FCC) cites three factors impacting rural call completion: uncaptured or incorrect signaling, the presence of automated call traffic, the price disparity to deliver calls to rural operators, and the increase in vacant phone numbers. These all work together to reduce the capability of legacy network performance metrics to measure network health. Using actual data from interexchange carriers and our understanding of the symptoms of the connection problems, we created a new metric, called Human Retries (HMR). We designed HMR to be as independent from these factors as possible. The intent of HMR is for it to be deployable and to identify and resolve problems with calls to rural areas on a real-time basis. While we were unable to completely disentangle HMR from some issues that cause problems for the legacy metrics, we were able to detect anomalies that potentially indicate problems that the other metrics were not able to capture. This paper describes the successes of the new metric, as well as identifying where more work needs to be done to further reduce the influence of the complicating factors and to determine whether the data anomalies represent actual problems in the network