[Updated 7:49 am, 8/1/2012] We have been informed by the phone carrier that this issue has been resolved. The problem was apparently a hardware failure in a key piece of equipment.
[Updated 4:54 pm] As of about 4-4:15 pm, This problem has resurfaced, although log distance calls are displaying various symptoms. The phone carrier is working on the problem.
This morning there have been reports of certain long distance calls not connecting, giving “dead air” when dialed. This is due to a problem at our telephone carrier, which is experiencing a widespread issue. The carrier is working on the issue, which is affecting all their customers. Long distance calls appear to be working now, but this may be sporadic for the next hour.