Blocking that port without potentially making a large portion of the Internet inaccessible is much more difficult. TCP, on the other hand, can be configured to use port 443, the same port that handles that vast majority of Internet traffic.

This makes it relatively easy for Internet service providers (ISPs) or network administrators to block it. UDP uses port 1194, which is the default port for OpenVPN. Learn more: What’s the difference between UDP and TCP?

A port is the endpoint or point of origin for your online traffic. While TCP and UDP handle these packets differently, the more important property when it comes to evading VPN blocks is what port they use. These protocols both determine how the Proton VPN app sends and receives the data packets that make up your Internet traffic. OpenVPN, the VPN protocol that our Windows app uses, supports both the User Datagram Protocol (UDP) and the Transmission Control Protocol (TCP). Our new Smart Protocol feature ensures this will never happen to you again. Have you ever had your attempts to connect to our VPN repeatedly fail while you were at work or university? There’s a good chance these networks were blocking the transmission protocol you were using. Version 1.10 of our Windows app has the Smart Protocol feature, and it will automatically connect to the next best server if your VPN connection attempt fails. The latest version of the Proton VPN application for Windows adds two new features that make it even more secure and easier to use.

For mac instal ProtonVPN Free 3.1.0