A software glitch caused the intermittent failure of telephone calls statewide for eight hours Wednesday, and affected emergency calls to 911 as well.

The 911 system itself, however, was not the problem and was never down, a Hawaiian Telcom spokeswoman said.

The problem had been resolved by mid-afternoon, she said.

The source of the trouble was software in Hawaiian Telcom’s call-processing equipment, which allowed only some calls to go through, said Ann Nishida Fry, Hawaiian Telcom spokeswoman.

Technical problems caused intermittent communication problems with landlines and some cellphones serviced by Hawaiian Telcom on all islands. The problems occurred from 6 a.m. to 2 p.m., with residents unable to call into any county police departments.

“We’re going to address it so this does not happen again,” Nishida Fry said. “It was not a 911 issue or outage of any sort. It was a problem with voice calls being completed. The 911 system was not down.”

Nishida Fry illustrated the intermittent problem, saying, “In my office, I could make and receive calls at one point, and 10 minutes later I could not.”

Hawaiian Telcom initially said the intermittent voice call problems occurred from 6 to 9 a.m. Some callers received an “all circuits are busy” message, while others got a busy signal.

Then at 9:45 a.m., Hawaiian Telcom said it had used a temporary routing solution to reduce the volume of voice calls affected.

Meanwhile, the Honolulu Police Department asked the public to limit 911 calls to emergencies.

Sarah Yoro, HPD spokeswoman, advised cellphone users to send text messages to 911 if voice calls did not go through.

“The text message should include the type of emergency service needed (police, fire or ambulance), the location of the emergency and a brief description. Callers who send texts must enable location services on their mobile devices,” Yoro added.

At 11 a.m., the police department said all emergency calls still were not connecting with police dispatchers.

Internet and data services were not affected during the outage.

Fry could not say how many Hawaiian Telcom customers were affected.

Maui County officials said any network issues with 911 calls were resolved before noon, including on Molokai and Lanai.

During the outage, the Hawaii County Police Department said those in need of police assistance should report to the nearest police station or flag down a police officer.

Kauai County officials reported that its 911 and other lines were fully functional as of 10:30 a.m.