People responded so strongly to the BlackBerry service outages that you'd think the city's whole power grid had failed.

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Reasons Behind BlackBerry Service Outages

Since September 2007, BlackBerry Internet services have been significantly disrupted at least four times. Two of the major outages occurred within just 10 months of each other. Previous outages have occurred but didn't get the publicity because the devices have not always been so widespread.

BlackBerry outages first appeared on the public radar in April 2007. From the evening of April 17 until the following morning, millions of BlackBerry users across North America and parts of Europe and Asia found themselves unable to access the Internet or send and receive e-mail. They could, however, still make phone calls and send text messages.

RIM, the company behind the BlackBerry, doesn't go into much detail regarding the causes of the outages. In this instance, however, the company said the problem was triggered by a software upgrade designed to provide faster access to data. Instead, the upgrade unexpectedly interfered with communication between the system's database and its data storage, so information couldn't be transferred to individual users. To compound the problem, RIM's backup system also failed. The double failure led to a mountainous backlog of e-mails.

A similar failure occurred just 10 months later on Feb. 11, 2008. This time, RIM explained (vaguely) that the three-hour outage stemmed from a problem with upgrading the service's internal data routing system.

Part of the reason that some BlackBerry outages are so noticeable is that RIM only has two data centers to handle the e-mails of its millions of subscribers. One center is in Canada and handles messages in the Western Hemisphere and parts of Asia, while the other is in the U.K. and handles traffic from Europe, Africa and the Middle East.

The two network operation centers, or NOCs, receive e-mails from a company's e-mail server, confirm the users and then forward the messages to the corresponding BlackBerry. Other makers of smartphones, like Nokia and Microsoft, don't have centralized data centers, so if they were to have an outage, it would only affect a single company or operator -- much smaller in magnitude than the BlackBerry outages.

Not all BlackBerry users are equally affected by outages. Corporations and government organizations with their own internal e-mail setup often subscribe to the BlackBerry Exchange Server, or BES. With this service, companies have their own server on-site and thus are less prone to blackouts. Individuals, however, use BlackBerry Internet Service, or BIS, where e-mails are pushed from the mail account on an individual's computer, through one of RIM's data centers, to the individual's handheld device by phone carriers like AT&T.

The outages in September 2007 and February 2008 only affected users of the BlackBerry Internet Service. In these instances, BlackBerry services were temporarily interrupted or delayed because of maintenance, and large corporations didn't notice a thing.

But what happens when they do? Learn more about some of the potential side effects of BlackBerry outages on the next page.