[aprssig] Explain path please

[Cap Pennell]

Yes, all basically correct.  Path traceable from left to right in the
packet.  Your own TNC adds the "*" after the callsign of the digi you heard
(some mark earlier ones too).  Some digis don't leave the WIDE1 showing
after use, though they do properly insert their own callsign into the
packet's path history.  "Traceable WIDEn-N".

N8JE-9>APT406,W4MIN,WIDE1,WC4PEM-10,WC4PEM-14,WIDE2*,qAR,KC4ZVV-2:!2716.84N\
08150.06Wk028/010/A=000101/Scanning Local Repeaters

The three-hop path taken by N8JE-3's packet to the IGate shows left to
right:

N8JE-9 > W4MIN > WC4PEM-10 > WC4PEM-14 > (KC4ZVV-2 IGate)

N8JE-9 had set the station's path to WIDE1-1,WIDE2-2
More often, three-hop paths aren't needed, and setting WIDE1-1,WIDE2-1 is
better (two hops in all directions).
http://info.aprs.net/index.php?title=Paths

73, Cap KE6AFE


-----Original Message-----
From: aprssig-bounces at lists.tapr.org
[mailto:aprssig-bounces at lists.tapr.org]On Behalf Of Lynn W. Deffenbaugh (Mr)
Sent: Sunday, October 19, 2008 16:32 PM
To: noskosteve at yahoo.com; TAPR APRS Mailing List
Subject: Re: [aprssig] Explain path please


Steve Noskowicz wrote:
--- Lynn  wrote, with Steve's interjected comments:
WIDE1-1,WIDE2-2
W4MIN heard the signal, consumed the WIDE1-1 and repeated
(probably with
WIDE1*,WIDE2-2)
WC4PEM-10 heard that, consumed one of the WIDE2's and
repeated (probably
with WIDE1,WIDE2-1)
WC4PEM-14 heard that, consumed the final WIDE2 and repeated
(probably
with WIDE1,WIDE2*)
KC4ZVV-2 heard that and gated it to APRS-IS


Close.  As I understand it, each digi that hears AND sends should add
it's own ID.


Words can get in the way sometines.  I believe Lynn is correct, but I'd pick
a nit and modify it this way:

  Each digi, in sequence, that is in the path to the IGate, that hears AND
sends it on to the next digi, will add it's own ID. The digi that uses up a
path designator, marks it with "*".

  Shouldn't  the "WIDE1" be "WIDE1*" - indicating it was used up...or is
that stripped off to shorten the packet?


That has bothered me.  Note that in my comments I had the WIDE1* on what was
likely transmitted by W4MIN, but all subsequent transmissions do not include
the *.  I wish I understood why the consumed portions didn't keep the *, but
in my experience and with my setup, only one station ever has a * indicator.

I believe it is also likely that when WC4PEM-10 transmitted the packet with
WIDE2-1, it probably had a * on its own station ID which was subsequently
removed by WC4PEM-14 when it consumed the remainder and transmitted WIDE2*.

Lynn (D) - KJ4ERJ