A SIP request made by %1 failed in an unexpected manner (status code %2). More information is contained in the following ...

A SIP request made by %1 failed in an unexpected manner (status code %2). More information is contained in the following technical data:
 
 %3 
 Resolution:
 If this error continues to occur, please contact your network administrator. The network administrator can use a tool like winerror.exe from the Windows Resource Kit or lcserror.exe from the Office Communications Server Resource Kit in order to interpret any error codes listed above.