On Fri, Aug 14, 2009 at 2:14 PM,
usna71<[email protected]> wrote:

> Can anyone help me understand this path?
> KB1MOV-1 2009-08-14 13:42:48 - 2009-08-14 13:42:49
> [APOT2A via W1UWS,WIDE1*,WIDE2,qAR,W1XM]
>
> I believe W1XM was the iGate, but W1UWS is a mountaintop
> digi.  Am I correct in thinking it is functioning as a local digi?

It is acting as a FULL digipeater. Mountaintop (WIDE area) digipeaters
respond to WIDEn-N, including WIDE1-1.

>  Did it respond to the WIDE1?

Actually WIDE1-1, which was decremented to WIDE1-0, which is shown as
WIDE1. The * depicts the has-been-digipeated bit, which indicates to
the next digipeater to hear the packet that the WIDE2-1 portion is
next to be used. It does however show us that there's a digipeater in
the area that is not doing proper callsign substitution.

2009-08-14 11:42:48 MDT: KB1MOV-1>APOT2A,W1UWS,WIDE1*,WIDE2-1,qAR,KB1POR-1
2009-08-14 11:42:49 MDT: KB1MOV-1>APOT2A,W1UWS,WIDE1*,WIDE2,qAR,W1XM

The first packet path above shows the next hop in the path to be
WIDE2-1, but KB1POR-1 heard it direct from W1UWS, and forwarded it on
to the APRS-IS. However, another unknown digipeater appears to have
acted upon the packet, using up the WIDE2-1 path, but did not insert
it's callsign, nor did it mark the used path with the
has-been-digipeated bit, before W1XM sent that packet to the APRS-IS.

Also, from what I can see of the packet payload, both copies appear to
be identical, which should have meant that the packet forwarded by
W1XM should have been dropped by the duplicate packet filter. There
must be some unseen difference in the two packets that allowed it
through. That would suggest that something out there is modifying the
packet in some way.

Just remember that WIDE area mountaintop digipeaters respond to
WIDEn-N including WIDE1-1, whereas home fill-in digipeaters should
only respond to WIDE1-1, and no other combination of WIDEn-N values.

James
VE6SRV

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