SINGAPORE - Extensive tests were carried out on M1's mobile network as it was being upgraded - but even these could not prevent an unexpected congestion problem which the telco blames for its service outage one week ago.
To ensure such disruptions do not recur, the telco said on Monday that it has taken steps to improve the network. Detailing the preliminary findings of the incident, it also clarified that the latest downtime was not related to the service disruption of almost three days in January last year.
However, M1 said it could be related to the overall upgrading of its network which was also linked to M1's outages in October and December last year.
The congestion problem in last week's incident had spread to different layers of its network, interrupting the process of confirming that people making calls on it were indeed M1 customers.
It led to many being unable to make calls for more than five hours from 7am. Text messaging and data services were mostly unaffected as they use different processes.
The congestion issue arose from call confirmation equipment that had intermittent connection problems. M1 said these problems were unexpected and have not been seen elsewhere in the world.
The root cause for the equipment woes is still being investigated by M1's United States-based provider, which it declined to name. M1 added that it has made changes to this equipment and is also looking to enhance software to better manage sudden and unexpected congestion issues.
M1 took to Facebook to keep customers informed during last week's outage, but many of the 3,800 comments to its post were furious about the breakdown. Customers in the Central Business District, Bukit Batok, Clementi, Sengkang and Pasir Ris were among those affected.
M1 spent around $125 million on a project to upgrade its network which is slated to be completed in the third quarter of this year. Intensive tests were carried out as the telco moved calls to a platform that uses Internet broadband lines to transmit voice data instead of circuit switchboards. It was meant to reduce the number of dropped calls, speed up calls and improve their quality.
M1 said the upgrade allows functioning parts of the network to more quickly take over those facing problems. Chief executive Karen Kooi said: "As with any new system, we need time for it to stabilise and to work out the issues."
She added that M1 hopes "to eliminate unexpected (events) beyond our control from occurring".
On why the telco had decided to use the new technology, Ms Kooi said: "If we waited for technology to mature, we would still be waiting today. We have always prided ourselves in investing in the most advanced technology."
SingTel said that last year it implemented a network management solution that can also automatically have working parts of the network take over from components that face problems or congestion.
Mr Mock Pak Lum, StarHub's chief technology officer, said it relies on "tried-and-tested hardware and software to distribute traffic on our mobile network when necessary and to minimise any downtime". He added: "As with any new and untested mobile network technologies, there are higher risks. Hence, we monitor such technologies closely before any implementation."
Minister for Communications and Information Yaacob Ibrahim hit out at M1 last Wednesday, noting that its updates to customers on the downtime could have been better.
The telco explained on Monday that it had updated customers through Facebook, its corporate website, call centre hotlines and shops.
"We regularly review our customer communications to identify relevant and effective channels for keeping our customers updated, and will continue to do so," M1's spokesman added.
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