http://example.com/api/swsend.asp?username=xxxx&password=xxxx&sender=senderId&sendto=919xxxx,919xxxx&message=hello&dlrUrl=http://yourServer_Url?logID=$logID$%26phNo=$phNO$%26result=$result$

public function sendMessageCallback() {

    $responseBody = file_get_contents('php://input');

    $data = array('value' => $responseBody, 'date' => date('Y-m-d h:i:s'));
    $this->db->insert('test1', $data);
}