My problem started out as poor bandwidth between a 64 bit Win 7 Home OpenVPN server in location A (Northern Europe) and a Win 7 or Linux Client in location B (Southern Europe).

Location A has FTTC 70Mbps/20Mbps

Location B has FTTH 60Mbps/10Mbps

Both connections work well up to their expected limits, except when connecting machines at each location directly to each other (e.g. first openVPN running with server at Location A and client at Location B, typically seeing around 2 - 4 Mbps maximum down speed to the client and 5 - 6 Mbps up speed from the client through the tunnel).

Now I have tried TCP iperf between the two locations with both Win7 and linux at location B and Win7 at location A. In both directions I'm seeing only around 5 Mbps in either direction give or take .5 Mbps. When transferring data from Location A to Location B I'm expecting to see something much closer to the upload limit of the FTTC connection at location A (20 Mbps).

Trying speedtest.net from Location B picking a speedtest.net server at Location A sees the full bandwidth of the FTTH connection up and down at Location B, and similarly, trying speedtest.net from Location A picking a speedtest.net server at Location B sees the full bandwidth of the FTTC connection up and down at location A.

Any ideas what might be causing the problem or what would be the best next steps to further pin down the problem?


I think you may have a misunderstanding on how internet circuits are sold. You have 70/20 and 60/10 circuits. Those numbers are bandwidth to the core network of your ISP. They are not making any promises that you will be able to upload at 20Mbit to any place on the Internet, nor could they make that promise technically speaking.

Unless you have control over every hop in the routing chain between your locations, there is nothing you can do except talk with your ISP support.

If both sites are using the same ISP (unlikely I suppose), you can request a point-to-point circuit from them, which will have guaranteed bandwidth.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.