BendBroadband technicians restored phone and Internet service Tuesday morning to about 3,000 customers in Bend and Sisters after a 3½-hour outage.

The problem lay in a universal broadband router, one of four that act as hubs for routing data traffic, said Krista Ledbetter, associate manager of public relations for BendBroadband and its parent company, TDS Telecommunications. She said technicians fixed the problem, but the root cause remains uncertain.

“While the issue has been resolved, we are continuing to work with our equipment vendors to ensure we have a clear understanding of the cause for the service interruption,” Ledbetter wrote in an email.

The router handles data traffic for about 13,000 customers, she said. BendBroadband restored service to the last 1,400 customers around 10:35 a.m., she said. The company provides Internet access to about 43,000 customers.