Skaperen
when using UDP how can i have both ends trying to establish a tunnel send datagrams to each other when starting, to try to establish the tunnel symmetrically? the idea is to "punch a hole" through two firewalls at the same time. both of these firewalls normally do not allow incoming traffic except as configured (and that option is not easily available). both do allow outgoing UDP datagrams from any inside address to any outside address. this means neither side can wait for the other side to initiate a request because the receiver's firewall will be stopping such datagrams. both of these firewalls do temporarily open a reverse path from the specific outside address to the specific inside address as a result of an outgoing datagram being sent from that inside address to that outside address in order to allow for response datagrams, and keep it open for some period of time that has been determined to be at least one minute in time. what i would like to do is have OpenVPN initiate setting up the tunnel from both ends at nearly the same time so that each is opening a way for the other to communicate. it would also be helpful to repeat trying to establish the tunnel at a rate with an interval of slightly less than every minute. i suggest every 50 seconds with plus or minus up to 6 seconds of random jitter in fine increments. how could this be done?
