What is OpenVPN Protocol?
By Paul Liu
Monday, January 7th, 2013

OpenVPN is an award winning open source protocol used to deploy virtual private networks (VPN). Backed by OpenVPN Technologies, a privately held company, it is one of the most advanced VPN protocols available today which has helped to make VPN technology safe and secure. With over 5 million users and 150,000 downloads every month, OpenVPN holds a dominant position in the open source VPN space which is expected to grow even further in the coming years. In this article, we list down the features of this protocol along with its pros and cons.
History
The OpenVPN project was kicked off as an open source project in 2002. James Yonan was one of the key persons behind the project who later co-founded OpenVPN Technologies along with Francis Dinha. The basic idea of OpenVPN project was to develop a secure VPN protocol that supports remote access and allowed site-to-site or point-to-point connections through bridged or routed configurations.
System Support
Unlike other VPN protocols, OpenVPN is not bundled with any operating system. The setup and configurations typically requires installation of client software. The clients are available for Windows, Mac OSX, Linux, Solaris, NetBSD, FreeBSD and OpenBSD systems. While OpenVPN doesn’t support most mobile platforms such as iOS and Palm, it is available for Windows Mobile 6.5 and Android operating system through 3rd party apps. It is also possible to use OpenVPN on jailbroken iOS devices like iPhones.
Data Encryption
OpenVPN is one of the most secure VPN protocols available today. It used OpenSSL library along with different algorithms like 3DES, Blowfish, AES and RC5 to deliver the best possible security. A lot of VPN provider use 256 bit keys which provides a very good level of security.
Configuration
OpenVPN setup requires installation of a client software and configuration of files. Most VPN providers provide an easy to install client software which can be installed in less than 5 minutes. Depending on your VPN provider, you may also have to edit configuration files manually to correctly set up the OpenVPN client on your machine.
Speed
OpenVPN is one of the fastest VPN protocols available. For optimum performance, it is best to use the protocol in the default UDP mode.
Port
The OpenVPN protocol can be set up to run on any port through TCP or UDP. It can also be set up to use the TCP protocol through port number 443 which is the port used by HTTP SSL requests. This makes OpenVPN extremely difficult to block and enables it to bypass firewalls easily.
Stability
OpenVPN offers extremely stable connections even while operating in non reliable networks such as cellular and wireless networks. It also offers a TCP mode for unreliable connections but it is a lot slower due to inefficient encapsulation of TCP packets within a TCP connection.
Security Issues
OpenVPN is considered extremely secure and has no known exploits or vulnerabilities. Due to its support for highly cryptographic algorithms and use of pre shared keys, username/password or certification based authentication, it is considered very difficult to crack or exploit.
Conclusion
OpenVPN is one of the best VPN protocols available in the market today. It provides best speeds with unmatched security and is quite easy to set up. The only downside is that it is not yet available for all mobile platforms.
January 7, 2013