NComm 3.06/Term 4.28 ZModem Issues...
 

Hello fellow Amigans! :)

Once again I would like to ask for help in solving an issue I'm having.
I am currently using NComm 3.06/Term 4.28 with a WiModem232 to connect to BBSes over Telnet, and also doing testing having set up a BBS locally on my own LAN using Mystic BBS.

Everything works great aside from ZModem Uploading. When I try uploading a file from the Amiga 1200 using either the WiModem232, Telser.device and WLAN PCMCIA Card on Miami Deluxe TCP/IP Stack or even WinUAE with bsdsocket.library the transfer stalls and resends and eventually stops with NComm showing numerous transfer errors.

When using Term 4.28 however it works a LITTLE bit better. The upload starts, and then finishes (as long as the file is not too big), otherwise it either drops the connection to the BBS -or- it stalls out (without showing any errors).

Quite simply what I am wondering here is if there's a way to fix this to have file uploading using ZModem work reliably. I've read that SyncTerm on PC has a new ZModem implementation that is made to work well over TCP/IP, Telnet/WiFi link..... anyone know if something like this has been made for the Amiga/WinUAE yet?

//Prodigal Amigan.

ZModem has always been unreliable via TCP/IP in my experience. You could try lowering the connection speed.

Thanks for your suggestion. I have tried this without it making much of a difference unfortunately. I have the baud rate set to 57600 in NComm and Term and this is what I have the WiModem232 set to as well.

I'm kinda wondering if anyone has made an improved xprzmodem.library to cope with the differences in using ZModem over TCP/IP and Telnet link as opposed to using a dial up modem over the phone line. The ZModem implementation used in SyncTerm http://syncterm.bbsdev.net/ works absolutely flawlessly against my LAN BBS for both up and downloading at BLAZING speed (and against other Telnet BBSes as well).

Would be great if it would be possible for someone who knows programming to make a port of this Zmodem variant to the Amiga.

https://github.com/ftnapps/pkg-sbbs/...docs/sexyz.txt

I think the important features are:

* Handles Telnet IAC escaping and option negotiations
* Transfers files over fast connections (e.g. 100 KB/sec) without issue.

//Prodigal Amigan

That's an extremely high speed. Do you use the standard serial.device?

Yeppers peppers! Back when I had my old Amiga in the 90's I also always had it set to 57600 baud when dialling into BBSes and I never had any issues from it.

Now as far as the WiModem232/Telser.device is concerned I should point out that everything works *perfectly* when connecting to BBSes and downloading using ZModem and the issues as described only happens on attempting to upload.

From what I've been able to find out it seems the issue I'm having is with the ZModem protocol being used over TCP/IP. It works better in Term than NComm (where it doesn't work at all) but yeah if we could get a take on the XPRZmodem.library with the improvements from SyncTerm integrated in it (if that's even possible) - everything should work then. :D

//Prodigal Amigan

Well, try lowering the speed and try using v34serial.device or 8n1.device.

With telser.device my results are as follows:
NComm 3.06:
- Downloads work if zmodem ack is enabled
- Uploads does not work, same problem as you

Term 4.7:
- Downloads work
- Uploads work

It might be worth verifying which version of xprzmodem.library you are using also. There are several versions from different authors with incompatible versioning. The one which has worked best for me is the one that is included in Term 4.7 (downloaded Term from aminet).

Also remember that if you try several versions of xprzmodem.library, you must exit the using program and do an avail flush, else the old version will be left in memory (or reboot).

Thank you for all the information I will surely look into trying what you suggested as well. In my experience thus far downloading always works fine but its when I try uploading that things go badly.

In Term uploading works as long as I don't have too big a file to transfer, but if it is - after a while it stalls the transfer and sometimes seem to kick me off the BBS (when trying against my locally setup BBS on my own LAN).

//Prodigal Amigan

Update on progress with Zmodem Issues
 

Summed up I am still having issues.:crying

But this is what I've tried now (on my actual Amiga 1200!):

* Using 8n1.device instead of the regular serial.device under both NComm 3.06 and Term 4.7 (020+ version)

* Using the Super Zmodem XPR library instead of the regular xprzmodem.library

* Setting NComm/Term to work at a lower baudrate (19200) and adjusting the WiModem to work on the same baudrate...

* Downloads work perfectly using Zmodem under Term or NComm regardless of if I am using 19200/38400 or 57600 baud. No issues.

* Uploads stall "immediately" in NComm 3.06, with Term it starts the Zmodem transfer with several resends, sometimes reaching 100% and sending EOF, but then jumps back to ~15-20% and resends....

I find it incredibly frustrating that this happens trying to upload when downloading (using Zmodem on both NComm and Term works perfectly without a single hiccup. :banghead

/Prodigal Amigan

Perhaps the WiModem just isn't serviceable?

I find that very hard to believe. The hardware seems to be working perfectly aside from ZModem uploads. I've started looking at if there's an alternative to Zmodem that I could use for transferring files instead.

Best thing probably would be if someone ported SEXYZ from the PC (SynchroBBS/SyncTerm) to the Amiga (as an XPR library?) as this newer implementation of the X/Y/Z-Modem protocol takes the quirks of Telnet/TCP/IP into account when using ZModem to transfer files ....

It would be interesting to see if the problem with uploading files were to go away if I used a wired network card instead of WiFi .... but I have no way of testing this myself so....

//ProdigalAmigan

Some people on the bulletin boards I frequent use XModem for upload to get around their issues with ZModem.

I have a home-made SLIP-to-wifi adapter. You could use that with DCtelnet or telser.device.

telnet connection some times send garbage (Telnet command)
to transfer stream and you start to get packet error

ex. my C64 wifimodem do not transfer any files whit my BBS if
BBS side telser is setup whit Negations

if i xros "ignore Negotiation" transfer start to work 100%
so that's why i have Two nodes for Negotiation and none Negotiation

Same Problem
 

what is telster.device?

I am haveing the same problem as OP. Using wimodem232 and jrcomm and ncomm. Baud rate 2400 or 9600. serial.device set to same baud rate as terminal and wimodem232.

I cant upload or download using *ANY* protocol (x,y,zmodem) on a bbs.


Thanks,

m0e

Codetsu sorry I didn't see this posting until now. I have setup Mystic BBS on my PC running it on the LAN. Do you know if it would be possible to "ignore negotiation" in that software package somehow? I'll look around and hopefully find something)..... :cool

You can use zmodem with AmTelnet, in my experience that works much more reliably than with telser.device and terminal programs.

Thanks for the suggestion Kolla! I'll definitely check it out soon.
About to head out here now so will have to do it a little bit later :)
But thanks again for the suggestion! :)

Just remember to have the zmodem libraries available, I simply do this by having Term_4.8/Libs as part of my LIBS: assign. :)

That is correct. The issue is that the ZModem protocol was designed for land-line use with a known maximum latency period (<50ms). Because TCP/IP packets are subject to random (and typically long) latency periods, ZModem won't work unless you can adjust the various internal parameters to allow for small size and long delays between packets. You have to remember that with a WiFi modem, like my WiModem232, you are dealing with communication to/from the WiModem, router, ISP, and connecting points. Ping times can be several hundred milliseconds long when spanning the globe, and often >50ms even within your own country.

Y-Modem, Y-Modem-1K, and Y-Modem-G are the best protocols to use with WiFi modems.