In A Nutshell
OpenVPN is generally best type of VPN connection to use, because it cannot be blocked simply by cutting off traffic to a specific port. L2TP security is excellent, but it requires the use of a specific port, making it fairly easy to block it using a firewall. PPTP is not secure enough for use in such situations. OpenVPN, however, is secure and it can bypass national firewalls.
This will unblock sites like Gmail and YouTube and make all your internet connections encrypted. If you want to read more about how a VPN (Virtual Private Network) works see this article.
You can also set up Obfsproxy. Here are some instruction from BestVPN:
Obfsproxy is a tool designed to wrap data into an obfuscation layer, making it difficult to detect that OpenVPN (or other VPN protocols) are being used. It has recently been adopted by the Tor network, largely as response to China blocking access to public Tor nodes, but it is independent of Tor, and can be configured for OpenVPN .
To work, obfsproxy needs to be installed on both the client’s computer (using for example port 1194), and the VPN server. However, all that is then required is that the following command line be entered on the server:
obfsproxy obfs2 –dest=127.0.0.1:1194 server x.x.x.x:5573
This tells obfsproxy to listen on port 1194, to connect locally to port 1194 and forward the de-encapsulated data to it (x.x.x.x should be replaced with your IP address or 0.0.0.0 to listen on all network interfaces). It is probably best to set up a static IP with your VPN provider so the server knows which port to listen in on.
Compared to the tunnelling options presented below, obfsproxy is not as secure, as it does not wrap the traffic in encryption, but it does have a much lower bandwidth overhead since it is not carrying an additional layer of encryption. This can be a particularly relevant for users in places such as Syria or Ethiopia, where bandwidth is often a critical resource. Obfsproxy is also somewhat easier to set up and configure.
History Of Internet Blocking In Iran
There are over 36 million Internet users in Iran, according to EFF. These users are subject to very limited access to the Internet, however, and the restrictions appear to be getting worse. The Iranian government has expressed interest in filtering the Internet completely so that it meets their standard — and this means that there may be further restrictions coming down the line for Iranian Internet users. Already, bloggers and other individuals who have spoken out against the government online have been punished. EFF mentions that one Iranian blogger’s wife was beaten because of complaining of how security forces in the nation conducted themselves.
In October 2006, all Internet Service Providers (ISP) were mandated to cut down their download speed to 128kbits for private and commercial Internet users. In order to restrict internet access in Iran, the government uses SmartFilter content control software by Secure Computing which is based in San Jose. Also, it is alleged that Iran has electronic surveillance system made by Nokia Siemens Networks (NSN).
Recently, Iran passed legislation which stipulates that Iranian ISPs must keep all data received and sent data, and the data is not deleted until 3 months after the contract of the client has expired. ISPs also filter sites with pornographic and political content in nature.