How would you tunnel through GFW?
abalashov: OpenVPN + NAT.Unlike most VPN technologies which rely on additional encapsulation in Layer 3/4 like GRE and IPSec (which have signatures that can be filtered out easily without deep packet inspection), OpenVPN works over userspace TUN/TAP drivers and a UDP transport.  So, it just looks like plain old application-layer UDP traffic.  The standard port it uses (1194) can be changed easily.Although not impossible, it would be very hard to block something like that without catching in the same rules many other ordinary applications that use UDP, such as most online games, Skype, etc.It does, however, require that you tunnel to a concentrator outside the GFW.