[aprssig] bad Mic-e packets
oh2kku at iki.fi
Sat Apr 22 01:59:11 CDT 2006
Doug Ferrell wrote:
> I'm seeing bad mic-e packets (er...reported to me as being bad) at my Igate
> station with the "]" bracket. At first I thought it was aprsd but I went
> into terminal mode and I see the same thing. So I guess this is a TNC setup
> problem? Below is a snippet that I edited to eliminate the callsigns so it
> starts after the colon.
I can't say for sure for those packets you showed, but a fact of life is
that aprsd (the sourceforge.net version) breaks certain mic-e and some
other APRS packets. It does that by replacing bytes that are under 32
and over 126 ASCII value with a space. To be exact, it uses the
isprint() function for determining whether to pass a byte or to replace
it with a space. This bug has been there for ages and still is in the
"current" (May 2003) release version.
Sometimes I see mic-e packets that have been truncated, possibly by some
other piece of software that removes bytes with ASCII value under 32
from packets. I guess it is also possible that the TNC you are using has
a setting for passing only printable characters.
More information about the aprssig