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List:       mumps-l
Subject:    Re: sorry about that.
From:       Eli Reidler <eli () pds ! ascendia ! com>
Date:       1999-07-20 14:30:24
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It was my intention to post to the group about this zmodem and telnet info but I
wanted to get some feedback first.  So I wanted to send it to some acquaintances
first. But I hit the REPLY key and didn't notice the address it picked.  I
wanted to present it a little nicer.

So I'll reply to Urs's questions.

On Tue, 20 Jul 1999 13:53:55 +0200  [7:53 AM our time], Urs Achermann
<urs_ach@email.com> wrote:

> Hello Eli,
>
> Never mind sending it to the group. :)
>
> Ehm, the bit you wrote about zmodem over telnet and stuff sounds quite
> interesting.
>
> We connect to our client's systems through modems attached to one of our
> RS/6000 and then use telnet over this connection. The thing is, with this
> concept we cannot transfer files between the systems.

Can you connect to your client from your RS/6000 via telnet directly?  Is your
system and/or client's system on the internet?   If you can, then you would be
able to connect via telnet directly from the MSM application instead of having
to do it from the unix prompt.  I did this using TCP SOCKETS and telnet
negotiating.  (The routine can also connect via a direct TCP socket connection).
I assume your system or the client's system is not on the internet since you are
dialing out via modem instead of telnetting (unless maybe your client has a
firewall set up).  So you can also open a serial modem device and dial into
another system directly from you MSM application. Sounds like you're dialing
into a terminal server and then telnetting over into your destination system.

Once you make that connection, you would be able to hit a key or two (you could
define the key sequence like CTRL-A) and a screen would pop up to allow you to
upload/download files using zmodem, ymodem, ymodem-g, xmodem 128, xmodem 1-k,
xmodem crc or xmodem checksum.

Since the telnet session adds and subtracts some negotiating control characters
during the send and receive process, the file transfer programs do not work
because checksums and CRCs will fail.  So I have added a flag to my file
transfer programs to be aware of when it is in a telnet session and to add and
remove the negotiating control characters when necessary.  This puts the file
transfer back on track.

However, I do not understand your issue.  If you are telnetted from your
client's termial server into his system and you transfer a file from/to his
system via your modem - there should be no problem.  All the telnetting issues
should be appropriately handled between his terminal server and his computer and
you should be getting clean data?  so what exact problem do you experience?

I guess FTP is the way one is supposed to transfer files from system to system
when the normal connection is via telnet.  Maybe I should get the FTP specs and
write that in MSM too?

Hope I answered your question.
Eli

> In other words, I would be interested in your programs, so I should be
> grateful if you could elaborate this to me.
>
> Greetings from sunny Switzerland,
>
> urs.

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