Originally posted by diwakar

When I do it through telnet, I get the same error:

SQL> connect dcbl/dcbl@dcbl
ERROR:
ORA-12154: TNS:could not resolve service name


Warning: You are no longer connected to ORACLE.
When you telnet to the box hosting the database, you need not give the connect string (provided you have only one service on the box).

Just give...

connect dcbl/dcbl


HTH.