Singapore telco M1 Limited (M1) has shared their preliminary findings from its investigation on the service disruption that occurred last week.
Last Tuesday (4 February 2014), M1 customers reported that they were unable to make voice calls, send SMS or access mobile data services from 7am to around12.30pm. Preliminary investigations suggest that an unexpected processing software issue had prevented M1's customers from registering on the mobile network.
The issue was said to have originated from a pair of mobile site switches which performed in an unstable manner, therefore causing intermittent connection problems between the telco's switches and customer databases.
M1 explained that its customers need to be authenticated by its network before they can make voice calls. As the intermittent connection interrupted the authentication process, these unsuccessful authentication attempts tied up network resources and led to congestion at the customer databases. The congestion then cascaded to another network layer, tying up additional network resources and preventing customers from making or receiving calls.
While the full investigation is still ongoing, M1 is "reconfiguring its site switches to eliminate congestion that may arise due to unstable intermittent connections," said Karen Kooi, chief executive officer of M1.
M1 has also taken steps to prevent similar incidents from occurring in future. Kooi said that besides deploying a software enhancement to allow M1 to better manage sudden and unexpected extreme traffic conditions, the telco will also appoint an independent expert to review its network architecture and connectivity.
Sign up for CIO Asia eNewsletters.