How to put a public IP address in a device behind a tunnel?

Hi,


I have a SIP phone that requires a public IP address, no NAT at all. My public IP addresses are in the datacenter, where my Linux servers are located. At home, I have a RB751U-2HnD. I have to make the SIP phone belive it is directly connected to my network at the datacenter so I can set a static IP address to it from the IPv4 block I use in the datacenter while in fact, the SIP phone is connected to my Routerboard at home. How can I achieve this?

My first though was: I should run pptpd or OpenVPN as a server in a Linux box at the datacenter and then configure my RouterOS at home as a VPN client. But what would be the next step?

Thanks in advance.

Run l2tp as you can bridge it.