ORA-24247: network access denied by access control list (ACL)

------- ACL
DECLARE  
  l_acl_name         VARCHAR2(30) := 'ftp_conn_test.xml';
  l_ftp_server_ip    VARCHAR2(20) := '134.239.239.3';
  l_ftp_server_name  VARCHAR2(20) := 'bsnet-test';
  l_username         VARCHAR2(30) := 'TEST';
BEGIN
  begin
     dbms_network_acl_admin.drop_acl(  'ftp_conn_test.xml'     );
  end;
  DBMS_NETWORK_ACL_ADMIN.create_acl (
    acl          => l_acl_name,
    description  => 'Allow connections using UTL_TCP',
    principal    => l_username,
    is_grant     => TRUE,
    privilege    => 'connect',
    start_date   => null,
    end_date     => NULL);
  COMMIT;
  DBMS_NETWORK_ACL_ADMIN.add_privilege (
    acl         => l_acl_name,
    principal   => l_username,
    is_grant    => FALSE,
    privilege   => 'connect',
    position    => NULL,
    start_date  => NULL,
    end_date    => NULL);
  COMMIT;
  DBMS_NETWORK_ACL_ADMIN.assign_acl (