Connect_Error when trying to connect to Oracle remotely

[samira]

I'm using Oracle database pulgin and it works fine when I have localhost in server field, but when I try to connect to Oracle on a remote mahcine in my local network it provides me with CONNECT_ERROR.

I'm sure port#, SID ,username and password are correct . Tried with SQLPLus from my machine and it connects successfully. ( TNSname.ora is checked as it's fine)

Has anyone any idea what could be the issue ?