The Dublin/Worthington side of the COIRS system went into site trunking  just after midnight this morning for approximately 8 minutes. We discovered that  OarNET, our connectivity provider to the master site in Delaware, was conducting  another round of switch upgrades like they conducted back on September 16th.  However, in this instance, they failed to notify us of the work so we could be  prepared. 
We have talked with OarNET and reinforced the importance of advanced notice  for any work being performed on our circuit. They apologized and assured me they  are taking steps to improve notifications. 
Sorry for the inconvenience last night and we want to assure your staff and  users that we are working with OarNET to ensure it doesn't not happen again.  
