What equipment to combine clients into one network via VPN, L2TP protocol (without IPSec)?

Question

VPN

It is necessary to combine up to 40 3G-4G routers into one network (communication operators are supposed to be different) and up to 20 PCs with a wired Internet connection. That is, up to 60 clients in total within a private network. Traffic between devices is not expected to be intense, with a peak load of up to 0.4 Mbps from wireless routers.
Will it be an acceptable solution to this problem to buy a PC with some characteristics (as an option - a regular office PC for MS Office, etc.), install Windows Server 2012 R2 on it and raise an L2TP server on it using standard Windows tools, to which data will be connected 60 clients? This PC is planned to be located behind a router (ASUS RT-N16, custom firmware from enthusiasts), wired Internet connection, channel according to the tariff plan 100 Mbps.
Can this server handle 60 VPN tunnels at this speed? What should be the hardware of this server in order for it to cope? If you need to describe in more detail the maximum speeds of clients, then I can do it, just please indicate what information is required and affects the choice of hardware.
And also another question - there are productive, expensive and not very routers on the market that can act as a VPN server, and in what cases does it make sense to use them and does it make sense to do this to solve the described problem?

Answer 1

ZyWall can do this even in the younger current series, but the price is biting.
But he knows exactly.
Mikrotik will also drag, while you can take a more productive option for the same money. I recommend it.

Answer 2

It will be cheaper, faster, easier, more flexible to do everything on mikrotik.

Answer 3

My opinion is Mikrotik.
I have this one at home, it pulls 40 clients without any problems (the load is small)
https://mikrotik.com/product/RB962UiGS-5HacT2HnT
I would set some similar one for the task -
https://mikrotik.com/product/RB2011UiAS -2HnD-IN
Option two - download the x86 version of Mikrotik on a PC.
Option 3 - install pfSence fully - it will also work without any problems.
Option 4 - install fully Zeroshell - it will also work without any problems.
About vpn - I would use openvpn. it crawls so far everywhere, with pptp, for example, there was a problem through Rostelecom, there were glitches and breaks. But in another city on the same provider there were no glitches) so here how lucky

Answer 4

In my opinion, having suffered in due time with all sorts of VPNs, there is no better solution than openVPN! Works on Windows, and on OSX, and on a bunch of routers, with branded and custom firmware. A server with an old Core i3 processor keeps 100 clients calmly + plus three virtual machines (telephony, base and web cameras), but this is under Linux.
Mikrotik and ubiq have an openvpn client / server for sure, well, in all Linux ones. There are also in android :-)
PS. At the moment I observe about 40-45 clients, but they are not permanent with us, they will go out, then they will go out.