FTP problems with IBM 390 server

I am using the FTP library from QNX’s free SW web site under QNX 4.25. I have it working fine with NT and QNX servers. It has one problem using an IBM 390 mainframe as the server. When attempting to abort a data transfer, the 390 seems to ignore the abort command. After the timeout, the 390 responds to the next command with the abort response. From here on in, all responses are “behind” by one command. The abort sequence is done as follows:

First 2 telnet commands are sent
IAC IP (interpret as command, interrupt process)(binary 255, 244)
IAC DM (interpret as command, data mark)(binary 255, 242)
(note the IAC in this command is sent as out of band data)

Then the string “ABOR” is sent.

Does anyone has any ideas what is wrong? The QNX command line client is able to abort a file transfer with the 390 server.



Jack Rosenbloom
Webcraft Mail Systems
Manager, Process Control Systems Engineering
4371 County Line Road
Chalfont PA. 18914
Phone: (215) 997-5269
FAX: (215) 997-5455
E-Mail jrosenbloom@webcraft.com