A ‘Who’s Who’ of VPN Protocols: Explaining PPTP, L2TP, Open VPN and SSTP

Our lives are increasingly becoming more digital.  Every year a new iPhone is launched with more apps that do more for our convenience. From big CEO’s to elderly grandmas and grandpas, technology has spread throughout our lives like a cancer. With whistleblowers like Edward Snowden revealing NSA plans to break into our privacy, to legislators arguing over internet privacy laws, our digital world is no longer safe. A Virtual Private Network (VPN) is one way to stay safe in a digital world of hackers and malicious people bent on stealing your identity.


VPN technology works on protocols. But what is a VPN Protocol, what types are there and what does each one do? Here we will try to explain this rather technical information in an easy to understand manner. Hang on to your hats; it’s going to be a bumpy ride.

VPN Protocols

First, let’s recap. A Virtual Private Network (VPN) is a network of computers that allow users to connect to restricted and blocked websites. Through the use of tunneling, encrypted data gets sent from one server to another. But there’s a little more to it. This all happens by the use of VPN protocols. VPN protocols are, simply put, a code of conduct for data packets. Protocols are the information one system uses to send data to another; information like error detection, authentication of the sending system, signaling and how the data is represented to a receiving network.

Originally, in the dial-up days, this was done with a PPP or Point-to-Point. Data was bundled up and neatly packaged, encrypted and framed. PPP sent this data bundle over the dedicated lines from one computer to another. VPN tunneling protocols work much the same way, with one difference.

PPP was only designed to handle one system to another and one data packet at a time. One of the main reasons that, in the dial-up days, when you downloaded a large file, the rest of your web session slowed down to a snails crawl. VPN tunneling protocol allows multiprotocol traffic encryption and must faster speeds.

Whew! Okay, now let’s look at the types of VPN tunneling protocols, namely PPTP, L2TP, Open VPN, and SSTP.

PPTP: Pont- to-Point Tunneling Protocol

  • The first tunneling protocol created; this is the most fundamental one.
  • PPTP is also the most unsecure. Based on PPP protocol, PPTP can be easily configured and easily unencrypted.
  • Used mainly by business for remote access
  • Low bit- encryption levels make for faster connections; 40-bit, 56-bit, and 128-bit encryption levels
  • Not flexible
  • Uses 1723 TCP port
  • Easily blocked- fixed protocols

L2TP: Layer 2 Tunnel Protocol

  • By itself, not secure. Paired with IPsec
  • Found in all devices that enable VPN
  • NSA top-secret AES 256-bit encryption
  • 500, 1701, and 5500 UDP ports
  • Encrypted twice- high overhead
  • Easily blocked- fixed protocols


  • Open source VPN
  • Extremely difficult to block
  • Uses flexible encryption; 160-bit or 256-bit
  • Can be configured for any port; works best on UDP ports
  • Highly configurable, but difficult
  • Best VPN protocol

SSTP: Secure Socket Tunneling Protocol

  • More secure than PPTP; solution to PPTP decryption issue.
  • Mainly Windows only; will work on Linux and SEIL
  • Highly secure; 256-bit encryption
  • Uses 443 TCP port
  • Hard to block when using SSL
  • Easy setup on Windows 7

Final Analysis

Many VPN Providers offer a free VPN account and free VPN proxy. Be careful of these for they use PPTP protocol. For the best VPN protocol technology, OpenVPN is the most secure with the most flexible encryption. There are some VPN providers that offer a free VPN account and free VPN proxy through OpenVPN, but with everything else, know who you’re dealing with, “for all that glitters is not gold.” –William Shakespeare; The Merchant of Venice (1596).

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