Step 1 Log in to the Huawei server and capture packets.
Step 2 Observe the data packet, and check whether the IP address carried in the SDP packet returned by the lower-level platform is an intranet IP address (shown in the ellipse in the following figure). The video stream is kept alive based on this IP address. If the IP address is an intranet IP address and cannot be accessed directly, network address translation exists between the Hikvision platform and the Huawei platform.
Step 3: Modify the configuration on the Hikvision platform. Change the intranet address to the NAT address. After the modification, play videos from the IVS client. If the videos are not stuck after 30 seconds, the fault is rectified. If all videos are suspended after 30 seconds, go to Step 4. If one video is normal but other videos are suspended after 30 seconds, go to Step 5.
Step 4: Capture packets on the Hikvision platform. It is found that NAT exists between the Huawei platform and Hikvision platform. As shown in the following figure, the address from the Huawei platform to the Hikvision platform is converted to 18.104.22.168. The source address of the RTCP packet received by the Hikvision platform from the Huawei platform is not the actual IP address of Huawei server. The Hikvision platform cannot identify the IP address. As a result, the stream keep-alive fails. Modify the network configuration of the firewall so that no address translation is performed when the Huawei platform accesses the Hikvision platform. If multiple videos can be played on the IVS client, the fault is rectified. If only one video is normal and other videos are stuck after 30 seconds, go to Step 5.
Step 5 Analyze the data packets captured in Step 1 and filter out RTCP packets, as shown in the following figure. Check whether the source IP address in the RTCP packet received by the Huawei platform is the same as the IP address of the stream keep-alive address in the SDP packet. The stream keep-alive address in Step 1 is 63.27, while the source address in the RTCP packet sent from the Hikvision platform is 63.254, indicating that NAT has been performed (for multiple times), and the address is converted to 63.254. You need to modify the network configuration of the firewall so that the source IP address received by the Huawei platform is the same as the stream keep-alive address in the SDP packet.