Phone calls from Everbridge to contacts in China fail and the call result is:
Not Delivered – Downstream Communication Error
Not Delivered - Voicemail Hung Up
At a minimum, calls to China should adhere to Caller ID requirements called out in the Solution section below.
However, even with proper Caller ID in place, China has very restrictive requirements, regulations, and filtering for voice calls. As a result, voice calls from Everbridge Suite going to China may be blocked even when best practices and recommendations are followed. Blocked calls will typically generate a "Not Delivered - Downstream Communication Error" or "Not Delivered - Voicemail Hung Up". We highly recommend being multi-modal and not relying solely on voice calls to reach your contacts in China.
Ensure the Caller ID is from that of the originating country. For example, if you use everbridge.net, then your calls to China should be configured with a valid +1 phone number. If this does not solve the issue, then please refer to knowledge base article 000065291 - Troubleshooting: Known Voice Call Limitations and Anomalies.
As an alternative, consider using other delivery paths such as email and SMS. Such delivery paths are not affected by these regulations. Per the Everbridge CARES Best Practice Program described in knowledge base article 000063755 - CARES Best Practice Program, it is encouraged to use multiple delivery paths to reach contacts.