Connecticut’s health insurance exchange, which has largely avoided the technical problems that have plagued the federal website, was caught in the middle Sunday when it was no longer able to verify information through the federal data hub.

Terremark, a Verizon company that operates a data center for the federal government, was trying to replace a networking component Sunday when it brought the entire network down.

Connecticut residents will still be able to log onto Access Health CT and create an account and comparison shop, but no one will be able to actually sign up for a plan until Terremark resolves the problem.

A spokeswoman from Access Health CT said Sunday that they were contacted by the U.S. Centers for Medicare and Medicaid Services about the outage and were unable to give any indication of when it will be fixed.

“The application and enrollment system on and the Data Services Hub is down because Terremark, the company that operates the data center that hosts the website and the Data Services Hub, experienced a failure in a networking component, and planned maintenance to replace it brought down network connectivity to the data center,” Kathleen Tallarita said in a statement Sunday. “Our understanding is that this failure is likely impacting several other sites, in addition to and the Data Services Hub. Terremark is working to resolve the issue as quickly as possible.”

Terremark is a Verizon cloud computing service that received a $15.5 million contract from the federal government.

The federal data hub is the portal that all 50 states use to verify an individual’s identity and income in order to qualify for the subsidized health insurance plans.

The server lost connectivity after workers tried to replace a failed networking component, U.S. Health and Human Services Department spokeswoman Joanne Peters wrote in an e-mail to Bloomberg Businessweek. Peters didn’t say when the failure happened or how long it would take to repair, according to reports.

Connecticut is one of 14 states that have opted to set up their own exchanges. However, even though it has its own software and servers it’s required to communicate with the federal data hub in order to verify information like the identity or income of an individual applying for coverage.

The federal site, which is being used by 36 states, has been plagued with problems since enrollment began on Oct. 1.

Even President Barack Obama acknowledged the problems last week saying that it “is not working the way it should for everybody — there’s no sugar-coating it.”

The problems have prompted calls from some members of Congress to delay the penalties for those who remain uninsured. Meanwhile, the administration has said it’s willing to extend the enrollment grace period until March 31.

Last week, the U.S. House of Representatives Energy and Commerce Committee held a hearing where it grilled four of the contractors who worked on the site.

The problems, according to experts, go well-beyond the large volume of people logging in all at the same time to compare plans. They were “caused by inadequate server capacity, poor software coding, and system architecture.”

The U.S. House of Representatives Energy and Commerce Committee will hold a hearing Wednesday to hear from officials at the U.S. Health and Human Services Department, including Secretary Kathleen Sebelius.

The U.S. House of Representatives Ways and Means Committee has scheduled a hearing Tuesday to review problems the administration is having implementing the new law. Medicare chief Marilyn Tavenner is expected to testify.