Yes, an ISP can limit the speed of a VPN.
Yes, an ISP can limit the speed of a VPN.
I recently started using NordVPN and immediately noticed a problem: whenever the connection is active, speeds stay below 25mbps. I have a 100mbps plan, and this issue affects all devices on my network—phones, PCs, laptops. I’ve tried various troubleshooting steps with customer support, but nothing has resolved it. Since it’s happening across the board, I suspect either my router or the ISP is the cause. Using a manual OpenVPN profile for NordVPN works okay and provides around 70mbps in both directions, though it’s UDP and TCP-based, which can be inconsistent in speed and latency. It’s worth noting that switching to OpenVPN inside the NordVPN app doesn’t help; it only functions when connected via the OpenVPN GUI. I’d like to connect through their NordLynx protocol, which uses WireGuard tunnels. Please share any speed tests or diagnostic logs you have, and attach the diagnostics file if possible.
It might be poorly configured due to an overly small packet size. Please verify and modify it accordingly as shown below.
You're questioning whether TCP or UDP is more suitable for your connection. It seems like you're trying to use both simultaneously, which isn't possible. If your ISP experiences high congestion or packet loss, TCP tends to perform better than UDP. It's probable that TCP gets higher priority, particularly when using port 443 and if the network doesn't inspect packets, it treats them as regular HTTPS traffic. While Wireguard claims better resilience to congestion, I've noticed it can be more inconsistent than OpenVPN even with UDP. Its advantage in unstable networks is that it avoids dropping connections since it doesn't track individual links, but this also makes it prone to staying on servers with packet issues, whereas OpenVPN would typically switch to a different server upon reconnecting.
In the NordVPN app you can choose the VPN protocol such as NordLynx, OpenVPN TCP or OpenVPN UDP. When using any of these, your download speed is capped at 25mbps. If you stop using the NordVPN interface and instead download the OpenVPN app from openvpn.net, applying a configuration file from the NordVPN site improves performance. You then achieve around 70mbps with either TCP or UDP protocols. I was hoping to use WireGuard mainly for gaming and streaming because network interruptions are an issue. The VPN is necessary since there were recent problems with submarine fiber links between India and EU servers last year, causing latency of 300-350ms compared to the usual 100-120ms. Using a VPN likely helps by changing the routing path, maintaining similar ping times around 10ms.