Ideal for countries with elevated censorship
Many countries have developed automated firewalls that can perform deep packet inspection (DPI) on-the-fly. This allows them to restrict access to well known VPN protocols such as IPSec or OpenVPN in real time without the need of compiling large databases of VPN IPs to block.
Because of that, such protocols are not suitable for use in countries where governments spend millions and billions on restricting on-line freedom. Come StealthVPN (TM), Astrill's answer to VPN traffic profiling. Bypass firewalls designed to limit VPN technologies with one click.