Hi Mohamed,
I assume you are using the S/4HANA 1511 30-day trial on CAL ?
Then, you need to open the respective port (Custom TCP, 30215) in CAL if not yet done (this is closed by default):
Click on the instance in the CAL console to bring up the instance details and then -> Virtual Machine -> Edit (right lower corner) -> Add (access point) -> Custom TCP Service on port 30215 for 'SAP NetWeaver 7.50 AS ABAP incl. SAP S/4HANA' -> Add -> Save.
Best,
Joerg