An April 9 and 10 outage that resulted in thousands...

and Transportation Commission (WUTC). The incident occurred when a public safety answering point trunk member (PTM) threshold counter, which routes calls to the appropriate PSAPs, ran out of capacity, CenturyLink said. The PTM is run by CenturyLink contractor Intrado, in the Englewood, Colo., Emergency Call Management Complex. When the counter reached capacity, calls couldn’t be assigned a trunk for delivery, said the telco. It said Intrado has increased the thresholds “so that it is not theoretically possible to exhaust the threshold ranges” and has created an alarm should the threshold be met. The contractor will also begin manually checking to see if the system is nearing capacity, said CenturyLink. A spokeswoman said the majority of the 4,500 calls impacted nationally were in Washington state but had no breakdown of how many calls were affected in North Carolina and Minnesota. John Garrison, director of the North Carolina Utilities Commission, said the outage affected PSAPs in a small number of rural areas in eastern North Carolina, and the PUC likely would not open an investigation. Intrado referred questions to CenturyLink. The WUTC has opened an investigation into the case (CD April 18 p11) and plans to hold an as-yet-unscheduled public hearing, a spokeswoman said. The Minnesota Public Utilities Commission isn’t investigating the outage, a spokesman said.