I have set up a service name that uses ODBC to connect to an external datasource on Win NT 4.0 SP6. When I do the Oracle Test ODBC it works fine. However, when I use the servie name I have set up I get the ubiquitous ORA-03113 error message. I have set the SQLNET.AUTHENTICATION_SERVICES to none. I have set up a trace and the only error is an "nioqer: incoming 12151 " line prior to the 03113 reference. I suspect some kind of authentication problem with the log on ID and password I am using to connect to the data source that is occuring somewhere on the network. Does anyone have any experience working through this type of problem?? Any suggestions would be appreciated !! thanks !