All systems in the Dallas data center are now performing normally.   Our engineers believe the cause was a routing problem at the data center that affected traffic from certain networks, resulting in slow or failing connections.  While messages were being processed throughout the duration of the routing issue, it is possible that some inbound messages to that data center may have been delayed.

All tests are normal at this point, and our engineers are continuing to monitor performance at the Dallas facility.  We will post an update if the issue recurs.