‘VPN’ stands for ‘Virtual Private Network’. Essentially, a VPN is a connection that uses a public network (like the thing you are using right now – the Internet!) to create a secure and private network, across which you can transfer data, and operate with anonymity. For more information on this, you can read a guide to the basics about VPNs here.
In order to transfer data VPNs use different ‘protocols’. As such, each VPN can be understood in terms of the protocols that they. There are a number of different protocols in use by VPN providers, with each being different in the way that it handles the data being transferred across the network. And as such, each protocol is suited to different needs.
Today we’ll be focusing on one particular protocol; the Secure Socket Tunneling Protocol, or ‘SSTP’ for short. SSTP is a tunnel used by VPNs which enables them to carry Point to Point Protocol (PPP) or Layer 2 Tunneling Protocol (L2TP) traffic through a Secure Sockets Layer (SSL) 3.0 channel. Sound confusing? It doesn’t have to be.
Essentially, SSTP creates a mechanism to transport traffic usually handled by other protocols. It is a super safe way of transferring data, providing transport level security with key negotiation, as well as encryption and traffic integrity checking. The authentication of the client is done during the SSL procedures, where a ‘handshake’ takes place – this is a process in which encrypted keys shared by the client and the server are swapped. When the keys match, the client is shown to be authentic and can proceed.
SSTP was developed by Microsoft and has the aforementioned security features. As such, it is a good piece of technology because it is generally considered a very safe protocol – but obviously there are complexities of how your VPN is set up and the system you are operating on. It’s also integrated into the latest Window’s operating systems and so is highly compatible and easy to use and maintain. What’s more, it can get past a variety of firewalls. However, although it is now supposedly available for Linux and RouterOS (amongst other systems), it’s best performance is with Windows.
For more information about protocols and all things VPN, click the button below: