An SMS gateway manages the sending and receiving of SMS transmissions to or from a wireless network. It sits between the subscriber who needs to send/receive SMS and the short message service center (SMSC). The SMS gateway is available when Wireless mode has SMPP enabled or Wireless-C mode has CMPP enabled.
After you have defined SMS gateways, you associate them with the MPE device to mange the sending and receiving of SMS messages. You can define a maximum of 10 gateways. The default gateway is configured in the Policy Server Configuration section using the Policy Server tab.