Hi alzhao and many thanks for giving me your help.
Now i have been able to make Vpn client functioning (i don’t know how, i believe that before i tried to connect in UDP).
I observe a strange thing, when the Vpn client is connected another device (tun0) becomes active and that is the device of the vpn client but if i execute netstat -r i can see that there are two default gateways, one regarding tun0 and the other regarding my adsl router.
If i go to analize my internet traffic i can see that i am going out with adsl router and not with tun0 as i expected (see pic attached).
Where is the problem ?
I have my device connected with my adsl router with wan (DHCP address 192.168.1.2) and to my home hub with lan (IP address 192.168.8.1), is it correct ?
Many thanks in advance