[aprssig] KISS mode TNC and aprsd?

Chris Kantarjiev cak at dimebank.com
Thu Jul 19 01:54:04 EDT 2007

I don't really know where else to ask questions about aprsd, so y'all are it.

I'm back to trying to turn my little Linksys WRT54 into a digipeater/igate,
after several months away. I got digi_ned running on it pretty easily,
but digi_ned doesn't have igate functionality. Henk's cunning plan for
that is that you do some ax.25 plumbing to copy packets to an igate 
program. Fine, there's an OM in Germany who has built the ax.25 stuff
for the WRT and published the binaries. Load that.

Find out that KE7BAP has compiled aprsd for the WRT. Load that.

Stumble about trying to understand ax.25 configuration on linux.

Discover that the embedded digi_ned that is available for the WRT doesn't
have ax.25 compiled in. Neither does the aprsd. Bah.

A little discussion leads to the idea of putting the (KISS) tnc on a serial
port and turning it into a KISS ax.25 port, and then using net2kiss
to replicate that stream on a couple of ptys, and feed one to each
program. Brilliant! Much hilarity ensues when we discover that 
net2kiss insists on legacy pty naming, but the WRT's kernel exposes
Unix98 pty names. 

Excitement and glee when I figure out that the kernel still has legacy
support compiled in, and I can create the right devices and have it work
(and even better when I find the right devices).

OK. Get it all set up. See packets come out both ptys. Start the programs.
digi_ned works like a champ.

aprsd does not. it connects to the core server as it should, and sends
net beacons. It never sends anything from rf. Dig into the rf.log file and
find that the packets are all bogus and truncated.

Tear out hair. Google and read a lot. Consult with KE7BAP. Oh. He's
running his KPC3+ direct, and not in KISS mode.


It appears that aprsd is willing to deal with KISS on an ax.25 port, but not 
from the TNC. At least, not with my config.

Is there some magic by which I can get aprsd to talk to a KISS TNC? Please?

73 de chris K6DBG

P.S. WA7NWP & I are already scheming about a net2tnc program that will
take the ax.25 port and turn it into a TNC stream on the pty. But that 
will take a little while to build...

More information about the aprssig mailing list