Bypass ISP blocking L2tp/ipsec VPN & Configure Linux Server

I want to bypass ISP blocking L2tp/ipsec VPN to use it from mobile device (Android & IPhone), knowing that the ISP has closed the following ISP (TCP: 1723, UDP&TCP: 4500), and opened (UDP&TCP: 1293, UDP&TCP: 1701, UDP&TCP: 1707, UDP: 1723). In case the freelance wants to use different than the above mentioned opened ports, they have to check with me before. The solution which will make the bypass ISP it should be configured on Linux server, and the Linux server should contain Radios server to manage the users. And it should be placed on a host company and there won’t be problem to use any version of Linux Server. Mobile users must use the native L2tp/ipsec VPN connection, without using any third party to make the connection. I will provide the Linux server. The project considered closed when I successful make a ( L2tp/ipsec VPN ) connection between a mobile device (Android & iphone ) to the Linux server.