From: Tomi Manninen (mdofh.jqkqt@nslnet.net)
Date: Thu Nov 08 2001 - 18:10:10 EET
On Thu, 8 Nov 2001, Laurie Brown wrote:
> Here is my problem:
>
> I have a Linux (Red-Hat 7.1 install) laptop
> connected via serial to a Kantronics KPC-3 TNC
> connected to a Kenwood Ham radio
>
> I need to send binary files from the laptop to the kenwood that will be
> recieved by a similar setup on the other side (Kenwood->Kantronics->laptop)
>
> This would be all without a human interaction.
>
> So, here is the question:
> 1) Do I use AX_25 to make this magic happen?
That is probably the easiest option considering it's ready in the kernel.
One could of course write a custom solution just for sending binary files
point-to-point on a reserved radio channel. That way you could cut the
protocol overhead to the minimum but it would also mean some extra work.
> 2) the AX_25 protocol seems to create a network socket - so how do you then
> send information out the serial port?
One option is to set up IP connectivity over the AX.25 connection. Then
you can use any of the well known file transfer methods over IP: ftp,
rcp/scp, rsync etc...
There are also protocols for file transfer directly on top of AX.25. These
might be more efficient in your case as the protocol overhead is smaller.
I'm not an expert on these, but YAPP at least is one protocol commonly
used.
> 3) Or, do I have to parse the text commands from the TNC and deal with it that
> way?
No. In fact for the Linux AX.25 support to work you need to set the TNC to
a special "KISS" mode where the TNC leaves most of the protocol handling
to the host system (your PC). In KISS mode your TNC won't even have a text
command set. Your KPC-3 manual probably has a chapter about KISS mode.
> 4) Is there any open source software out there that does this so that I can
> read though the code to see where my understanding of the problem is
> lacking?
The Linux kernel is of course open source. Several other AX.25 network
stacks exist that work in user mode (as opposed to kernel mode) that are
open source as well (JNOS and TNOS at least). However I'm not sure if
reading the source code of those gives you anything if you don't already
understand what they do.
Hopefully the above was of any help to you.
-- Tomi Manninen Internet: baf@helena.com OH2BNS AX.25: bpkb.lkqwpihtp@celestial.com.au KP20ME04 Amprnet: xgodrxad.nooqwmgzun@kmcmail.net- To unsubscribe from this list: send the line "unsubscribe linux-hams" in the body of a message to crmm@cofs.net More majordomo info at http://vger.kernel.org/majordomo-info.html
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