Yesterday, we noticed our OpenVPN based circumvention services stopped work properly. Looking into logs and with a bit of debugging we came to know that the TIC (Telecommunication Infrastructure Company of Iran), was interfering in all OpenVPN protocol handshakes. We managed to address the issue by changing the default initial handshake parameters (Link-MTU, Tunnel-MTU, Cipher length and SSL key size) and all systems are now nominal.
We’re proud to announce that our OpenVPN circumvention services are once again fully operational and working. :)