VPN Interoperability: How did we do it?
1. Connectivity Tester on VPN B sends a packet to Connectivity Tester on VPN E
2. VPN B device tunnels packet in IPSEC and sends to VPN E device
3. VPN E device de-tunnels packet and sends to Connectivity Tester on VPN E
4. Connectivity Tester on VPN E receives packet and sends response to Connectivity Tester on VPN B
5. B Tester receives response and updates web page