The BlackBerry wireless email service from Research In Motion appears to have suffered a widespread outage starting on the evening of 17 April in the US.
Customers on the BlackBerry Forums discussion board complained of having no service starting at about 5.15pm Pacific Time.
Callers to the BlackBerry US technical support line were still greeted with the following message early this morning (18 April): "We are currently experiencing a service interruption that is causing delays in sending or receiving messages. We apologise for the inconvenience and will provide updates as soon as they become available."
New York television news channel NewsChannel4 reported on 17 April that the problem affected "all users in the Western hemisphere". Postings to BlackBerry Forums indicated that the problem may be limited to North America, however.
"Officials with RIM said they are trying to reset the system and told NewsChannel4 that they are concerned that the backlog of data, which will rush through when it comes back on line, could cause a bigger problem," the news station reported on its website.
European users may have got off lightly. BlackBerry users in the UK seemed untroubled. A RIM official contacted in France was unaware of the problems, and said she had received messages sent to her BlackBerry as normal. Other RIM officials did not return calls seeking comment.
A spokesman for T-Mobile Deutschland was unaware of any problems, and BlackBerry users in Germany and France reported no interruption of service.
The outage may have been cause by one of RIM's Network Operating Centres (NOC) going down, according to Emma Mohr-McClune, principal analyst with Current Analysis. "This has happened before," she said.
RIM operates two NOCs, both located in Canada, according to Mohr-McClune. The company has considered locating additional NOCs outside Canada, she said.
Companies that provide BlackBerry service connect their mail servers to a BlackBerry Enterprise Solution (BES) server located on their premises, which in turn is linked to one of RIM's NOCs, according to Mohr-McClune. "All data slides to Canada and back," she said.
RIM may have been fortunate that the outage began at about 5pm Pacific Time, because it would have been after the busiest part of the US working day.
A representative for Taiwan Mobile, RIM's BlackBerry partner for the island, said the problem was limited to North America, and that users would not be affected unless they were sending or receiving email through a BlackBerry server there.
"RIM has not communicated with Taiwan Mobile about when this problem might be fixed," said the representative.
NTT DoCoMo in Tokyo said its BlackBerry users in Japan were also unaffected.
Peter Sayer, James Niccolai, Dan Nystedt and Martyn Williams contributed to this report