Hi all,
We encountered an issue where APNs (Apple Push Notification service) push messages cannot be received during development. The specific description is as follows:
Our app runs on an iPad that connects to the cellular network using a SIM card and accesses the Internet through the company's MDM, which provides APN setting proxies.
During operation, we found that the device fails to receive push messages from APNs. Network packet capture revealed that the connection attempt by apsd to port 5223 failed. According to Apple's documentation (https://support.apple.com/zh-cn/102266), when port 5223 cannot be connected to, it will fall back to port 443 and use a proxy. However, our packet capture showed that when port 5223 was unreachable, the apsd service on the iPad did not attempt to establish a connection to port 443.
Since the iPad device currently cannot establish a connection with APNs, it consistently fails to receive push messages from APNs. We tried disconnecting the SIM card and using a Wi-Fi environment, and in this case, the iPad device was able to receive push messages from APNs normally.
Could you advise us on how to proceed with troubleshooting in this situation?
