The rats_server's configuration is handled through two files called ratscal and ratsconf.
 

ratscal:
Ratscal is the client access list. It is the ACL for the rats_server program. It is a  text file consisting of entries separated by newlines. There should be one entry  in the file for each host that will contact the rats_server. Each entry will  consist of three elements separated/terminated with a colon. The first element  will be the host name, the second will be the first key in the key pair, and the  third will be the second key in the key pair, the fourth is a flag indicating if it is a master client daemon (1) or not (0), the fifth element is the port number, and only needs to be populated if it si a master client daemon. An example entries would look like:

foo.rutgers.edu:key1:key2:0:0

foo2.rutgers.edu:otherkey1:otherkey2:1:8910

NOTE!: key1 and key2 are restricted to a length of 56 characters each. An  entry with more than 56 characters will cause the server to FAIL ON  STARTUP.

 ratsconf:
 Ratsconf is the rats_server configuration file. It currently consists of 5 lines.

 ORACLE_USER:<username>:

 ORACLE_PASS:<password>:

 ORACLE_NAME:<database name>:

 DEBUG_LEVEL:<debug_level>:

 NETWRK_PORT:<port_number>:

Username is the username allocated to rats on the oracle server. Password is  the matching password for the username. Database name is the full name of  the remote database on the oracle server (for example test.world if the database  is configured to be in the world domain). Debug_level is an integer.  Don't  enter something bigger than MAXINT on your machine. The expected  numbers are between 1 and 10. 1 performs minimal logging, and 5 should  provide a trace file with numbers above 5 providing more trace details.  Port_number is the  port you want the server to run under. This should also  probably not be made larger than MAXINT.