How to connect to Oracle Database using SQL Plus?

I need to connect to a oracle database on a remote host (I have no oracle installed locally) using SQL Plus, I've already installed SQL Plus and looking on the internet got those way to connect but no one of them works on my case.

Some times I got this error:

ORA-12170: TNS:Connect timeout occurred

This is the way I'm trying to connect to oracle

sqlplus64 name_user/password@//remote_host:port/database_nae