the external program must understand telnet protocol. Otherwise, it can't send the
correct data format.
Peter Astrand wrote:
Hi. I'm trying to find a generic serial port redirection solution for a...
Linux terminal server environment. I'd like a solution based on RFC2217. I'm particularly interested in syncing Palm Pilot PDAs.
ser2net/sredird + Kermit ------------------------ Kermit has built-in RFC2217 support, but it doesn't work for me:
---
C-Kermit>set host localhost:4911
DNS Lookup... Trying 127.0.0.1... Reverse DNS Lookup... (OK)
localhost.localdomain connected on port 4911
C-Kermit>set speed 2400
localhost.localdomain:4911, 2400 bps
C-Kermit>connect
Connecting to host localhost.localdomain:4911
Escape character: Ctrl-\ (ASCII 28, FS): enabled
Type the escape character followed by C to get back,
or followed by ? to see other options.
----------------------------------------------------
,
Communications disconnect
---
Well, this was my fault: I didn't understand how Kermit worked. When using "set carrier-watch off", things worked much better.
* BUT: When using Kermit as a RFC2217 client for transferring files with
ZMODEM, I get "Bad CRC" pretty much all the time. This happens *both* with
the sredird, ser2net and Tactical Softwares Dialout/Server for Windows.
The problem seems to go away if I transfer files without "0xff" bytes(!) This looks like a Kermit bug to me. I'll guess I have to talk to the
Kermit folks about this.
* ser2net is totally incompatible with cyclades-serial-client. This is because ser2net interprets RFC2217 a bit differently. sredird sends command "101" as ack for command "1", while ser2net sends "1". RFC2217 is not very explicit about which way is most correct. The ser2net approach looks better to me, but the sredird one is probably more widely used (since Cyclades terminal server uses it, for example.) Probably, RFC2217 software needs to handle both cases.
Some more test cases:
* minicom + cyclades-serial-client + sredird: Works
* pilot-link + cyclades-serial-client + sredird: Does not work (see my previous mail)
* pilot-link + cyclades-serial-client + Dialout/Server:
Works perfectly.
* photopc + cyclades-serial-client + sredird:
Does not work. I get "excessive retries".
* photopc + cyclades-serial-client + Dialout/Server:
Works perfectly.
So, the combination of sredird + cyclades-serial-client does not work correctly.
Also, I tried running "Contract I.T. Communications Analyzer" on a Windows machine. One physical port was connected to a Linux machine via a null modem cable. This machine ran sredird. One virtual port was created with Tactical Softwares Dialout software, connecting to sredird. Communications Analyzer indicated 90% Byte Error Rate! Since cyclades-serial-client was not involved in this test, I would say that it looks like sredird is doing something wrong.
If *anyone* has any ideas of how to solve these problem, please let me know. I'm starting to run out of time and patience...
(Which mailing list is best for this topic?)
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