[Xastir-dev] What does "local" mean?

[Curt Mills]

I'm correcting an earlier message from me sent to this thread.  Also
moved this to xastir-dev list instead of xastir list:


When you have something like:

    WE7U>APRS,N7TAP*,WIDE3-3,WIDE:Something

It means it was heard direct from N7TAP.  When you have this:

    WE7U>APRS,N7TAP*,WIDE3-2,WIDE:Something

It means that one of the wide-area digipeaters sent it out (the
"WIDE3-2").  There's no asterisk in this case on the last station
that sent it.  Makes it a bit harder to determine who's local and
who's not.  In fact, we don't even know the callsign of that WIDEn-N
digipeater from this packet.

This packet:

    WE7U>APRS,N7TAP*,WIDE3-1*,WIDE:Something
or  WE7U>APRS,N7TAP*,WIDE3-1,WIDE:Something

Means that the WIDE3-1 was the last digipeater to be heard, and that
digipeater field is not used up.  How many asterisks appear depends
on the type of TNC receiving the packet (some put an asterisk for
every "digipeated" bit that is set, some put one only on the last
one).

So, here _should_ be the revised list of packets and which station
was heard last (listed at the end of the line):

    WE7U*>APRS,N7TAP,WIDE7-7,WIDE:Something     (WE7U)
    WE7U>APRS,N7TAP*,WIDE7-7,WIDE:Something     (N7TAP)
    WE7U>APRS,N7TAP*,WIDE7-2,WIDE:Something     (WIDE7-2)
    WE7U>APRS,N7TAP*,WIDE7-1*,WIDE:Something    (WIDE7-1)
    WE7U>APRS,N7TAP,WIDE7-1*,WIDE:Something     (WIDE7-1)
    WE7U>APRS,N7TAP*,WIDE7-1,WIDE:Something     (WIDE7-1)
    WE7U>APRS,N7TAP*,WIDE7-1,WIDE*:Something    (WIDE)
    WE7U>APRS,N7TAP*,WIDE7-1*,WIDE*:Something   (WIDE)
    WE7U*>APRS,WIDE3-3:Something                (WE7U)
    WE7U>APRS,WIDE3-2:Something                 (WIDE3-2)
    WE7U>APRS,WIDE3-1:Something                 (WIDE3-1)
    WE7U>APRS,WIDE3-1*:Something                (WIDE3-1)

So ST_DIRECT should be set for WE7U and N7TAP only if all of these
packets came in as shown.  The WIDEn-N stations don't have their
callsigns known in this case, so we can't mark them.  TRACEn-N is
the other case like this.  Can there be others?

Did you want to work on this Jack?  If not, I'll probably tackle it.
Olivier might be interested in checking the digipeater code in
Xastir (he's actually using it at home) and perhaps re-using some of
the logic there for this ST_DIRECT flag setting purpose.  Probably
you and he should talk.

-- 
Curt Mills, WE7U                    hacker_NO_SPAM_ at tc.fluke.com
Senior Methods Engineer/SysAdmin
"Lotto:    A tax on people who are bad at math!"
"Windows:  Microsoft's tax on computer illiterates!" -- WE7U
"The world DOES revolve around me:  I picked the coordinate system!"