What's the number of Changsha Unicom 3G calling card short message center?

Short message center, because the full name is short message service center (SMSC).

SMSC is a business processing system independent of wireless network. The main function is to submit, store and forward short messages. And complete the interworking with pstn (Public Switched Telephone Network), isdn (Integrated Services Digital Network) and PSPDN (Packet Switched Public Data Network), and transmit short messages between extended short message entity esme (External Short Message Entity) and MS (Mobile Station).

When sending a text message, the text message is actually sent to this so-called "short message center" first. Then send it to the user at the specified number through it. Usually, the number of SMS centers varies according to the number attribution. Only when the settings are correct can you send short messages normally. If the setting of the SMS center is different from the number attribution (for example, the number of city A, and the SMS center is set to the number of city B), you can only receive SMS, but not send it.