Asterisk PBX Tunnel - Repost - open to bidding

I need a tunnel to connect two asterisk (one on public ip and other on local lan) from firewalled lans with these features: - Encryption of VoIP data. - Traversal of any NAT and any Firewall. - Data compression levels over the tunnel to minimize throughput. - Use of HTTP or HTTPS or any other well-known port to transport VoIP data. - Customizable security levels with different encryption keys lengths and many encryption algorithms. Please bid only if you have worked with asterisk and tunneling.