Calls cut by failures in computer

Press, 18 February 1989, Page 9

Calls cut by failures in computer

By

DAVID CLARKSON

Telephone calls in central Christchurch were repeatedly cut yesterday by a series of failures in the computerised central exchange. The fault remained unidentified last evening, but about 6.10 p.m. the exchange was switched to an older computer programme to stabilise the situation. By that time a technician from the Wellington representative of the exchange’s manufacturer had arrived in Christchurch. The switch to the older, but proven, programme took several seconds and again cut calls, but it was the final act in a series of problems that had begun almost four hours before. The operations director for Telecom South, Mr Brian Finn, said the first failure' was at 2.25 p.m. Toll calls and local calls were lost. The local calls were partially restored, but the exchange failed again at 2.40 p.m. Mr Finn said it continued to be unstable throughout the afternoon. About 4 p.m. the exchange tripped out four times at 90-second intervals. The faults happened at

a peak traffic period, but Mr Finn said the amount of calls at the time was well below capacity. The exchange has a dual capability so that when a fault occurs, the programme can be “dumped” for checking while the exchange continues operating. But Mr Finn said the equipment did not allow this checking yesterday. While the software was being “dumped,” the remaining part of the computer would also fail. Mr Finn said he suspected a software fault was at the centre of the exchange failures, but he did not know whether it was linked to earlier problems. Those had been fixed as they occurred and traffic through the central exchange had been rebalanced, which improved its performance. The disruptions had occurred during peak business traffic, but the situation was stabilised in time for the evening’s peak traffic of residential and social calls. People had inundated Telecom South’s phones with calls reporting the faults, Mr Finn said. "We are very sorry when this sort v of thing happens,” he said.