Microsoft's BPOS cloud-hosted communication and collaboration suite suffered an outage on Wednesday, the latest in a string of technical problems in recent months.
The problem apparently lasted for more than three hours and involved a networking hardware problem that affected customers in North America, according to updates posted by Microsoft on the Microsoft Online Twitter feed and by administrators in discussion forums.
BPOS (Business Productivity Online Suite), which includes Exchange Online and SharePoint Online, has been hit by various outages dating back to August of last year.
Microsoft has at different times acknowledged the problems and apologized for them, pledging to do better.
In a statement on Wednesday, the company said the problem started at 11 am US Eastern Time, and confirmed that "network equipment issues" in the data centre were to blame.
"All services have been restored. During this incident, customers were updated via social media channels, as access to the Service Health Dashboard was impacted by this incident. We apologize for any inconvenience this has caused our customers," the statement reads.
However, as outages continue, the performance and reliability of BPOS fall further into question at a particularly bad time for Microsoft, which plans to launch BPOS' next version, Office 365, next week.
"E-mail downtime is always painful, particularly when e-mail is in the cloud and the customer has limited or no options to fix it," said Gartner analyst Matt Cain.
However, using cloud applications involves a certain loss of control by IT departments over things like outages in the vendor's data center, he said.
"Customers have to understand that part of the cloud deal is accepting a certain uptime service-level agreement, in this case 99.9 percent, suffering through outages, and getting the contractually obligated payback the vendor committed to if the SLA [service-level agreement] is missed," Cain said.
Microsoft has very high expectations for Office 365, which will offer significant upgrades over BPOS and is designed to compete better against rival offerings like Google's Apps cloud-hosted collaboration and communication suite.
For example, the Office 365 applications are based on the 2010 editions of their on-premise versions, while the BPOS applications are based on the 2007 editions. In addition, Office 365 offers the option of having Microsoft Office applications, which BPOS lacks. Office 365 can have Office Web Apps or the stronger Office 2010 Professional Plus suite.
In discussion forum threads, BPOS administrators expressed frustration with the string of outages and scepticism about Microsoft's ability to provide reliable uptime for the upcoming Office 365.