[jira] [Commented] (GUACAMOLE-860) Support for TN5250 terminal

["Nick Couchman (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/GUACAMOLE-860?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16910073#comment-16910073 ] 

Nick Couchman commented on GUACAMOLE-860:
-----------------------------------------

I'm continuing to spend time working on this as I have opportunity.  One of the things that has become clear as I've worked on this is that TN5250 is not so much an extension of the Telnet protocol as it is another protocol (SNA) encapsulated within the Telnet protocol.  It appears that many AS/400 systems provide some compatibility for Telnet when you connect from a standard client, but connecting from a true TN5250 emulator involves negotiation of the TN5250 protocol, at which point telnet is simply the transport used for actually getting the 5250 data between the AS/400 and the client.

Furthermore, the TN5250 protocol does some pretty interesting things.  I have a packet capture or two I'll try to attach, here, although I need to sanitize them a bit, but, whereas standard SSH and Telnet terminals write line-by-line and tend to clear and redraw the screen, TN5250 actually sends instructions for placing certain items at certain rows and columns on the screen.  So, implementing this in Guacamole is going to mean some more specific and direct manipulation of the terminal.

TN5250 also has exactly two sizes of screen - 24 x 80 and 27 x 132.  There's no dynamic sizing, and no other sizes.  There are a variety of monochrome and color options of these sizes, specified in the RFC linked above, but the sizes are fixed.

Finally, TN5250 does not use ASCII for its character set, it uses EBCDIC, so some amount of translation will need to be done between writing standard ASCII characters and emulating the IBM codepages.

None of this is to say it isn't worth doing - I actually think it would be really nice to have this as part of Guacamole, and I'll keeping hacking away at it.  It's just a little more involved than I first imagined :-).

> Support for TN5250 terminal
> ---------------------------
>
>                 Key: GUACAMOLE-860
>                 URL: https://issues.apache.org/jira/browse/GUACAMOLE-860
>             Project: Guacamole
>          Issue Type: New Feature
>          Components: Telnet, Terminal
>         Environment: IBM AS400
>            Reporter: Alessandro Sironi
>            Assignee: Nick Couchman
>            Priority: Minor
>              Labels: features
>
> In a scenario to give the possibility to work on IBM AS400 with all function keys working properly, there is the need to have Emulator 5250, the "simple" telnet could not support all the functions required to work properly on AS400



--
This message was sent by Atlassian JIRA
(v7.6.14#76016)