How to get TNS connect strings (like tnsping) to check a dblink via a session?

I would like to know, if there is any chance to get the currently used TNS connect string, that will be used for a DB-Link from a db-server. I'm connected to a schema on a database located on any server. Now, I have some database links, using tnsnames and which are currently not working properly. I would like to check, which target database is behind this identifier to verify easily, if this can be correct. If I would have OS access to the db-server, I would be able to read the ./tnsnames.ora or using tnsping. But the DDL of the dblink just uses the TNSNAME (RDBX in this example): > CREATE DATABASE LINK "ABC" CONNECT TO "RUSER" IDENTIFIED BY VALUES ':1' USING 'RDBX'; Of course, I could ask a DBA, but this is not always as easy in our environment and I would like to be able to double-check it myself without having OS-access.