how to communicate with ftp

here is my code :
//open a data socket
acceptSock = NetLibSocketOpen(gNetRefNum, netSocketAddrINET,
             netSocketTypeStream, 
             NetHToNS(6), timeoutticks, &err);
		
// Bind it to a local address
	bzero((char*)&address, sizeof(address));
	address.family = netSocketAddrINET;
	address.port;
	address.addr=0xc0a80011;
flag = NetLibSocketBind (gNetRefNum, acceptSock, 
       (NetSocketAddrType *)&address, 
        sizeof(address),  timeoutticks, &err);
// Set the listen queue size
flag = NetLibSocketListen (gNetRefNum, acceptSock, 1,
		   timeoutticks, &err);
	
// Get our local address of the data socket and use the port number 
		
	addloclen = sizeof(datLocAddress);
	addremlen = sizeof(datRemAddress);
flag = NetLibSocketAddr  (gNetRefNum, acceptSock, 
      (NetSocketAddrType *)&datLocAddress, &addloclen,
       (NetSocketAddrType *)&datRemAddress, &addremlen, 
       timeoutticks, &err);
	
// Get local address for the control socket. We have to use the IP address from
this socket since the data socket isn't connected yet.
	
	addloclen = sizeof(ctlLocAddress);
	addremlen = sizeof(ctlRemAddress);
flag = NetLibSocketAddr  (gNetRefNum, sock, 
      (NetSocketAddrType*)&ctlLocAddress, &addloclen,
      (NetSocketAddrType *)&ctlRemAddress, &addremlen, timeoutticks,
      &err);
	
StrPrintF(FTPCommand, "PORT 192,168,0,17, %d,%d\r\n", 
	ctlLocAddress.port >> 8,
	ctlLocAddress.port & 0x00FF);
	
flag = NetLibSend(gNetRefNum, sock, (void*) FTPCommand, 
	StrLen(FTPCommand), 0, (void*)&ctlRemAddress, 
	sizeof(ctlRemAddress), timeoutticks, &err);
	
	
now the ftp server show:200 PORT Command successful.
then I try to send a stor command to ftp server, I get a error
message:150 Opening BINARY mode data connection for test.txt.
        425 Cannot open data connection.

how can I open a data connection to send a txt file? please help me.