What are inband and out of band breaks?

Data exceptions like Control-C can be transmitted as part of the regular data stream (inband) or as a separate asynchronous message (outband). Obviously outband breaks are much faster as they can interrupt the flow of data.

Out Of Bound Breaks (OOB) are enabled by default. One can disable OOB from the SQLNET.ORA file:

DISABLE_OOB=on