| VCS Deployment Methods | 48Related tasksConfiguring H.323 SettingsIntelligent TraversalSome branch offices lack IT professionals, which means that professional network configuration (for example, theport forwarding) may be impossible. To solve this issue, Intelligent Traversal allows you to simply deploy your VCSin the intranet, and assign an IP address to VCS, which can be used to access the public network. After that you canplace calls to the VCS in the public network via your intranet VCS.Although this method is not applicable to the incoming calls.• Audio & Video Intelligent Traversal• Data Intelligent TraversalAudio & Video Intelligent TraversalWhen a VCS in the intranet calls the VCS in the public network, the audio & video streams send by the VCS in theintranet may carry the intranet IP addresses, as a result, the VCS in the public network fails to send the audio& videostreams to the VCS in the intranet. Besides, the problem of one-way audio or video and no image of the VCS in thepublic network may occurs to the VCS in the intranet. The above problems can be solved by the feature of audio &video intelligent traversal.This feature allows the VCS in the public network to check the media source address and the port of incoming RTPpackets, and then send the RTP packets back to the address where the incoming RTP packet comes from rather thanthe address provided in the Session Description Protocol (SDP).The following example illustrates a scenario about using the audio & video intelligent traversal:The VCS A locates in the intranet with the feature of audio & video intelligent traversal enabled, and the router doesnot support the ALG feature. The VCS B locates in the public network. A calls B, and then A sends the RTP packetsto the B.• If B disables the audio & video intelligent traversal feature, B will send RTP data to the negotiated IP address of A(private IP address provided in the Session Description Protocol), as a result, A may see black screen.• If B enables the audio & video intelligent traversal feature, B sends back RTP packets to the address whereincoming RTP packet comes from. A and B can communicate normally.• Configuring Audio & Video Intelligent TraversalConfiguring Audio & Video Intelligent TraversalProcedure1. On your web user interface, go to Network > NAT/Firewall > Intelligent Firewall Traversal > Audio & VideoIntelligent Traversal.2. Configure and save the following settings:Parameter Description Configuration MethodAudio & Video IntelligentTraversal Enable or disable the audio &video media stream to traversefirewall.Default: On.Web user interfaceData Intelligent TraversalWhen VCS in the Intranet calls the VCS in the public network, the VCS in the Intranet may fail to receive data (forexample: PC content and FECC protocol) from the public network. You can use data intelligent traversal to solvethese problems.
