Oracle Message NNC-00001 - maximum number of connections already open

ERRORmaximum number of connections already open
CAUSEAll available name service connections are handling requests.
ACTIONIf the problem occurs when running a name server, increase the values of names.max_open_connections. If the problem occurs in a client program, turn on tracing and re-execute the failing operation. If the error persists, contact Worldwide Customer Support.