What are the restrictions on outbound calling toward China?
- Chinese numbers cannot be used as “from” numbers for outbound calling purposes.
- Plivo recommends ensuring an average call duration of three minutes or more. Strict spam monitoring and general restrictions on VoIP in China mean that numbers involved in calls of less than three minutes have a high probability of being blocked.
- If you have a high volume of unanswered outbound calls, it’s likely that calls will be blocked.
- Don’t make calls from modified, spoofed, or restricted origination numbers.
- Avoid high volumes of repeated calls from the same origin number within one hour.
- Don’t use a toll-free number, as your calls will be blocked.
What are the restrictions on inbound calling toward China?
Chinese numbers can be called only from international, non-Chinese numbers. Any inbound calls with a Chinese caller ID will fail.