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

[BobDonnell at arkalmus.com]

I'd suggest that setting the ST_DIRECT flag should not be done on the
basis of having "heard XXX being used as a digipeater" e.g. N7TAP, since
that too can be aliased.  Something to consider is whether to code to
disregard any repeats heard of a particular packet - first one heard is
the only one analyzed.  Flush after a minute.

73, Bob

>-----Original Message-----
>From: xastir-dev-bounces at xastir.org
>[mailto:xastir-dev-bounces at xastir.org]On Behalf Of Curt Mills
>Sent: Thursday, January 16, 2003 11:25 AM
>To: Jack Twilley
>Cc: xastir-dev at krypton.hscs.virginia.edu
>Subject: Re: [Xastir-dev] What does "local" mean?
>
>
>
>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!"
>
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