2. China Unicom, the number of the short message center starts with +86 130 10, followed by 3 digits, which is the serial number of the short message center assigned by provincial branches), and finally it is generally 500.
3. The number of the information center, namely the Short Message Service Center (SMSC), is responsible for relaying, storing or forwarding short messages between the base station and the mobile station (ME); The protocol from ME to SMSC can send short messages from or to mobile stations, and the protocol name follows GMS 03.40 protocol.
4. The number of the information center is the short message server. If it is not filled in correctly, the SMS cannot be sent successfully. Each region has its own information center number. Please consult your local network operator for the specific number.