| VCS Deployment Methods | 49The following example illustrates a scenario about using data intelligent traversal:The VCS A locates in the Intranet and the router supports the ALG feature. The VCS B locates in the public network.The ALG feature on the router can temporarily map the port to a public port, which lasts 30 seconds by default. If theVCS B in the public network does not share content within 30 seconds, the mapped port will change, so that the VCSB may fail to share content with VCS A later. To solve this problem, enable the data intelligent traversal on VCS A,the VCS A will send keep-alive messages at regular intervals to keep the port open. Therefore, the VCS B can sharecontent normally.• Configuring Data Intelligent TraversalConfiguring Data Intelligent TraversalProcedure1. On your web user interface, go to Network > NAT/Firewall > Data Intelligent Traversal.2. Configure and save the following settings:Parameter Description Configuration MethodData Intelligent Traversal Enable or disable the PC contentand FECC protocol to traversefirewall.Default: On.Web user interfaceVPNThe VPN (Virtual Private Network) technology establishes a private tunnel on the public network through keyexchange, encapsulation, authentication and encryption, to ensure the integrity, privacy, and validity of the transmitteddata. VCS uses OpenVPN to achieve VPN feature. To prevent disclosure of private information, tunnel endpointsmust authenticate each other before the secure VPN tunnel is established. After you configure VPN feature on thesystem, the system will act as a VPN client and uses the certificates to authenticate with the VPN server.For more information, refer to OpenVPN Feature on Yealink IP Phones.• Related VPN Files• Configuring VPNRelated VPN FilesTo use VPN, you should upload the compressed package of VPN-related files to the system in advance. The fileformat of the compressed package must be *.tar. The related VPN files are certificates (ca.crt and client.crt), key(client.key), and the configuration file (vpn.cnf) of the VPN client.The following table lists the directories of the OpenVPN certificates, the key and the configuration file:VPN files Description Unified Directoriesca.crt CA certificate /config/openvpn/keys/ca.crtclient.crt Client certificate /config/openvpn/keys/client.crtclient.key Private key of the client /config/openvpn/keys/client.key
