@Clive_A 

120Mbps on client side and 1000Mbps on server side. I am just simple copying big file from server. I know that this is not exact methodology, but 1MB/s vs 10MB/s is big difference (I am not comparing 9MB/s vs 10MB/s). And I am comparing PPTP vs L2TP vs OpenVPN with the same server. If I am connected through OpenVPN on ER707 I am at least reaching 10MB/s. If I am connected to VPN (does not matter which protocol) through Windows 11 VPN client, I am reaching 10MB/s for all.

Specs from datasheet:

IPSec VPN Throughput: ESP-SHA1-AES256: 673.3 Mbps, ESP-SHA256-AES256: 650.2 Mbps/ESP-SHA384-AES256: 629.3 Mbps, ESP-SHA512-AES256: 633.8 Mbps
L2TP VPN Throughput: Unencrypted: 1243.7 Mbps; Encrypted: 561.0 Mbps
OpenVPN Throughput 135.0 Mbps

All speeds are much above my internet connection speed 120Mbps.

  @Clive_A 

No, I am comparing VPN client on ER707-M2 and VPN client on Windows 11. They are both connected from the same network and to the same VPN server.

  @Clive_A 

Yes, it is true, that there is a lot of reasons, but if it is working from computer on the same network (even through the same router), but the VPN connection is not established between router and server, but between computer and server, than problem is in the router capabilities. Could you at least show me some figure where ER707-M2 act as VPN-Client under PPTP/L2TP and it is reaching speeds more than 10MB/s?

  @Libik 

Hi, I did some testing here tonight. I have an ER707 and an ER8411 that I have tested with. I have not been able to test PPTP, but I have tested L2TP with routers as clients.

remote L2TP server is a UXG-Pro from unifi.

copying file from remote server to computer like you and the result is like this

This routers is connecte to same ISP so the result shuld be the same on both routers, but no.

ER707 120 Mbps (far away from greate)

to compare I also test ER8411 238 Mbps (Problably limit of the UXG-Pro)

But you have a much worse speed, it can be caused by OpenVPN.
what I see is that the L2TP speed goes down a lot when I activate the OpenVPN Client on the router,

try disabling OpenVPN to see if the speed on L2TP increases.

try and deactivate all tunnel exept tunnel you use for test and see if there is any difference when enabled or disabled.

  @MR.S 

I am connecting to the Unify Dream Machine Server for L2TP and Synology NAS for PPTP/OpenVPN. During the test I had only one tunnel active and all the others weredisabled. So for now I thinking about returning ER707-M2 and using old ER605V1 (which has almost same speed for me) and I have to look somewhere else for different router with really functional VPNs.

  @Libik 

I have two ER707-M2, they perform very well on IPsec Site to Site. I have a 500/500 Mbps line and it works fine on S2S. so it's a bit strange that L2TP is so bad.
I know there are many parameters when it comes to VPN, so slowness can be many places along the way.

Do you have a UDM or is it UDM Pro? UDM is a little weaker, so there may also be some limitations on it. If you have UDM Pro, I think it is the same hardware as UXG-Pro

Is your router behind another router? if you have the opportunity to do so, you can try to disconnect this so that you get a public IP on the ER707

@Clive_A when you test in lab do you get Encrypted 561.0 Mbps on L2TP. 

  @Libik @Clive_A 

Its something strange, when I do Site To Site with much stronger encryption than L2TP the speed is almost 80MB/s

On S2S I use this encryption

SHA-384 - AES256 - DH14
ESP - SHA-384 - AES256

This test is done with ER707-M2 and remote is a Cisco FPR-1120