Guilherme.
Thank you so much again by answering me.
Look this... What you tell me sounds a little bit strange because I got connection from PL/SQL Developer normally yesterday and today using the same credentials... see the print attached. Are the connection method and protocol different among SQL Developer and PL/SQL Developer?... also about TELNET is true we cannot connect at port 1521..... The hardest part is for the Oracle to work fine.. is very very necessary you have a infraestructure's team or even quite knowledge about "network" and so on..... Not seems possible to learn under Personal environment so it's much difficult to keep going. Instead of spending time to learn Outsystems development (quite interesting to me) I have first to learn so much about "network problems" to solve my Oracle connection (it's not interesting to me) because I'm a developer.
So, tell me... how can I get a local installation for learning?? Is there this option?? This way I could jump up this network problems whose expertise is missing to me.
Also I will try a VPN on RDS service even I don't trust on this.
Regards.
DARCIO DOMINGUES