Data Packet Damages
Symptom
When a packet verification error, packet loss, or packet disorder occurs during packet transmission between the engine server and client, the engine reports a VMI_ENGINE_EVENT_PKG_BROKEN event. A related message (the content depends on the ISV's implementation) is displayed on the GUI.
Impact on the System
When this fault occurs, the engine client cannot work. After reporting a VMI_ENGINE_EVENT_PKG_BROKEN event, the engine client disconnects from the server and exits.
When this fault occurs, the engine server disconnects from the engine client and switches from the online state to the offline state. In the offline state, apps in the cloud phone still run. However, in this case, touch input of the engine client cannot be received, and audio/drawing instructions of apps cannot be transmitted to the engine client.
Possible Cause
The communication connection between the engine server and client depends on the ISV's implementation. The cause of the data packet damage is related to the specific network connection mechanism.
- The typical TCP protocol is reliable. It can ensure that no packet verification error, packet loss, or packet disorder occurs during communication.
- The typical UDP protocol is unreliable. It implements a best effort approach, but may cause packet loss and disorder.
- If a component on the transmission path is faulty, some bits in the message packet may change, resulting in a packet verification error.
The instruction stream engine requires ISVs to provide reliable communication connections.
Procedure
- In the logs generated by the engine client, search for the log whose LOG_TAG is VMI_Communication and level is error, and then determine the cause based on the log.
- The communication connection between the engine server and client depends on the ISV's implementation. The cause of the data packet damage is related to the specific network connection mechanism. Provide the error information obtained in the previous step to the ISV for further fault locating.
- Reconnect the mobile phone to the cloud phone. The service recovers.