Capture and analyze packets on the VMU.
1. Log in to the VMU as user root and run tcpdump -i any -s 1500 -w /home/XXX.cap host X.X.X.X -vvt (X.X.X.X is the IP address of the Polycom platform).
2. According to the packets, at 16:11:33, the Polycom platform sends a recorded video playback request to the Huawei platform. The Huawei platform receives the message, but returns a 400 message.
3. Obtain PCG logs from the /home/ivs_pcg/mss-apache-tomcat/logs/PCG/debug directory. An error is reported at 16:11:33 in the log.
This indicates that the INVITE message is incorrect.4. Check the content of the INVITE message. It is found that the codes of the To and Subject fields in the INVITE message sent by the Polycom platform are the codes of the Huawei platform. According to the GB/T, the To field is the server code, and the Subject field is the camera code, as shown in the following figure.
5. The following figure shows a normal INVITE message. (The INVITE message captured on the FiberHome platform is used as an example.) If a normal INVITE message is sent, a 200 OK message will be returned.
6. After the INVITE message is modified on the Polycom side, the recorded videos can be played.