Re: [Linphone-users] Linphone call over SSH tunnel; RTP not connecting

[Stuart Gathman]

On 07/31/2017 07:53 AM, Stuart Langridge wrote:
>> Why is machineB only available via SSH?  Firewall?  NAT?
> This is the part that isn't changeable, I'm afraid; machineA
> and machineB are not accessible to each other, but they do
> have access to two SSH machines which _can_ see each other. (For
> various reasons I'm not really able to go into we can't use a
> "proper" VPN like openvpn either; ssh port forwarding is what's
> available. I know this isn't ideal for SIP/RTP calls, yep, and
> I appreciate you helping despite that!)
If there really is no UDP at all (not even to the two SSH machines),
then run openvpn over TCP between machineA and machineB (via a SSH
tunnel).    Then you can make normal direct calls between the private
(vpn) IPs of machineA and machineB.   Unfortunately, cjdns does not
(yet) support TCP connections.

You could also use sshuttle - a utility that forwards *all* outgoing TCP
connections over SSH.  If machineA and machineB both run sshuttle to
their respective SSH servers, and python is available on the SSH servers
(for the server end of the sshuttle connections), then machineA and
machineB can make arbitrary TCP connections to each other directly.