To enable BTS 3270 bridge support, you must specify the name of a bridge exit program on the BREXIT option of the TRANSACTION definition for the 3270 transaction that you want to run.
If two or more bridge transport mechanisms require the BREXIT parameter to be specified on the transaction definition, you can use an alias transaction definition. For information about how other bridge transport mechanisms support specification of the BREXIT parameter, see the CICS® External Interfaces Guide.