A call processing software issue might have been the cause of the service disruption experienced by M1 users in Singapore yesterday, according to the telco's preliminary investigations.
In a media statement, M1 said that the software had unexpectedly prevented its customers' devices from registering on the mobile network.
A full investigation will be carried out to determine the root cause of the incident, said Karen Kooi, chief executive officer of M1 Limited. She added that M1 will also be "appointing an independent expert to conduct a network architecture and connectivity review."
M1 users reported that they had difficulties making voice calls, sending text messages and accessing mobile data from 7am yesterday. Full service was restored at 12.15pm.
M1 said that the restoration work took time as the complexity of its network required it to troubleshoot the numerous interlinked network entities.
As a goodwill gesture, M1 will provide its customers with one day of free local mobile calls, SMS and MMS this Sunday (9 February 2014).
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