I have a couple of FritzBox routers at two locations set up with a site to site VPN always on. Works well, easy to see and access files at the 'other' location.
But when it comes to transferring large amount of data its quite slow. And my FTTC connection isn't anywhere near saturated. There's going to be some overhead for the VPN, but how much?
There's a 80/20 FTTC connection at one end sending to a 40/10 on the same ISP. So you'd think you could send at getting on for 20 Mb/s less what ever for the VPN as the receiving end can easily download that bandwidth. Especially as there's nothing else on the connection over the weekend.
Currently it sending at around 5000kb/s. The receiving FritzBox agrees! Surely I could be transferring at around twice that, maybe even up to 15 Mb/s?