PPTP vs L2TP through a router

I am a user of the unlimited tariff plan Corbina 10 Mbps. At home there is a Wi-fi router ASUS WL-520gc, it distributes the Internet to 3 cars, 2 of them via wi-fi. The problem was that when downloading from torrent networks (legal content), the speed could not exceed 800 Kb / s. First of all, I decided to call those. support. The first three “experts” switched me on for three minutes of the conversation, and in the end I finally got to a person with a very quiet voice. During a 40 minute conversation with breaks in musical breaks, we found out the following:

1. According to tests, the speed does not exceed 375 Kb / s.
2. But, with ftp.yandex.ru, the speed reached 500 Kb / s.
3. I am using PPTP connection type.
4. If you connect directly (without a router), the speed corresponds to the declared tariff.

The conversation ended with a 15 minute wait, followed by short beeps.
Sitting without a router was not cool, and I continued to search. Now in google. Walking through the forums, I found several solutions to the problem. People advised doing the following:

1. Disable the Corbina firewall on stat.corbina.ru . The idea seemed dubious to me, I don’t understand how port blocking can affect speed.
2. Remove Kaspersky. As far as I understand, this is the most common solution to any problem with any version of Windows. Be that as it may, I do not have Kaspersky, so I did not perform this step either.
3. Disable wi-fi encryption (I have WPA). It seems true, but did not want to sit defenseless (security, just do not start). Instead, I checked the speed when connecting to the router via cable. I did not notice any differences from encrypted wi-fi.
4. Switch from PPTP to L2TP, which is still under testing. Along with the advice there was an argument, they say, PPTP encryption implemented in this router is not hardware, but software, which dramatically reduces the exchange rate.

Reconfiguring the router to L2TP took one minute, and, lo and behold, the speed rose to 1.2 MB / s!

Conclusion

If you are connected:

1. Through the router.
2. By VPN.

And you have a low speed, check that the connection type (Connection type in the WAN settings) is L2TP.