But we want the tool which will listen on given port for connections unlike telnet. Thanks again to both of you, I really didn't know where to go next, you've been a god send.We are wellВ known about telnetВ which is pretty much handy tool to debug and open a TCP connection to remote server:port. I might have to see if I can go visit their office rather than adding additional confusion. The packets going down the tunnel as UDP. I realised tonight that the VPN was configured to allow clients to operate through a NAT device using UDP encapsulation. Something that might be causing ambiguity is that I've been using Cisco VPN to get to the train operators HIS server. Regard the choice of client, I've decided on Jagacy - it seems to be the only screen scraping library in Java (although unfortunately not open!). HIS-HIS bridge kinda thing? Atos allocate the train operator a number of sessions, currently 15 I believe (STK1 to STK15). Regards the config their end, I know the ibm mainframe is hosted at Network Rail, there is an HIS server hosted by Atos Origin, the train operators VPN into ATOS but also have another HIS server hosted their side. I've been reluctant so far to get in touch with Atos Origin to find out how it all works, albeit it only takes 5 mins to explain it takes about 3 weeks to find the person that knows the answer! I think I might have to, it'sД«eginning to sound a bit more complicated than I was expecting. STK8 is the available session on the HIS (which is located at 10.224.23.31) I appreciate you may never have used WinVV, but is there any chance you understand the fields in these WinVV connection params:

The only difference that I can see between winvv and the others is that winvv uses UDP and other emulators seem to use TCP. I'm just not sure how this can be the case, I've tried every combination of the config from winvv in other emulators with no success. Tried is config on the client rather than the server. This would therefore mean that the emulator that works correctly (WinVV) must be using telnet, and would suggest that the reason none of the other 3270 emulators I've I had a quick look at the link you sent over but I think the problem is more to do with the config on the HIS server as opposed TN3270 itself, although it was interesting to read about EBCDIC.ДЇrom what you say it sounds like the data can only be displayed over a telnet session.

The emulator that I downloaded had this option and when it was selected it required a LU/Device ID - is this the same as a session id? I wasn't aware that TN3270E was the mode required to HIS. I'm really puzzled as to where to go from here. It seems they are UDP packets with a destination port of 22102. Investigating further I captured the packets sent whilst connecting with WinVV. This seems really odd because I thought that anything that connected to a (telnet?) session needed to use telnet.

To investigate this I tried a simple telnet to the HIS server, expecting an error back stating it couldn't understand 3270 streams, but I'd like to use an open source telnet client rather than the WinVV one, and my problem is that they don't seem to work. When we connect in with a terminal emulator called WinVV (closed source developed back in the day by British Rail) we get a session that was specified inside the WinVV config and hey presto it talks

We have an HIS that has some (telnet?) sessions on it. I'm not entirely sure I understand the problem we're experiencing at the moment but I've hit a brick wall and really have no idea where to go from here.

How to use telnet to send udp