[CentOS] regarding vpn server for 1500 clients

> I have to build vpn server for 1500 clients. No encryption necessary.
> can anyone please recommend me vpn server.
>
> I do not have experience on vpn.
>
> I have tested openvpn on my test setup, & its working fine.
>
> I want to check if there any other vpn server available.
> I have not checked but can pptp vpn be usefull?
>
>
> My requirement is to connect 1500 clients on vpn server.
> Need frontend to manage vpn clients.

Have you looked at Mikrotik.com router OS?  It has PPTP server.  Very
fast and easy to setup.