Imagine I have a computer with two slow cheap internet connections from ISP A and B. I also have a VPS in a datacenter with very high infinite bandwidth.
I can make two VPN's. One from A to VPS and one from B to VPS. I can aggregate the two "virtual" tun interfaces, install a DHCP on my VPS and have a bandwidth that is the sum of the one possible with A or B alone.
By monitoring the bandwidth and adapt the load (for instance with ifenslave mode 5 or 6), everything could be balanced in a well better way that it would be possible with simple RR load balancing.
+- TUN: A ---- VPN ------+ | | Host - aggTun --| +-- VPS - DHCP--- WWW | | +- TUN: B ---- VPN ------+
However, this seems too good to be true and I strongly believe that this could have a bad impact on TCP connections (especially if the delays with A and B are differents). Do someone know what problems could arise and how could I solve them with a Linux environment?
Thank you very much and have a nice week