[Xastir] Still have questions if all is working correctly

[James Ewen]

On Fri, May 28, 2010 at 2:10 PM, Norman Heyen <n.heyen at comcast.net> wrote:

> When I look at the raw packets in APRS.FI (or any other site) all I ever see
> are the twice per hour beacons. When I look in the station info page, there
> isn't a section for "Stations which heard KC9NVN directly on radio". Even
> though I am acting as a fill-in in a fairly low traffic area, I would think
> that at some point I would transmit something to someone.

You probably do send packets out onto the RF network, however you are
connected directly to the APRS-IS stream


2010-05-27 13:10:10 MDT:
KC9NVN>APX199,TCPIP*,qAC,T2MIDWEST:=4217.27N108940.67W#XASTIR-Linux-Freeport,IL
2010-05-27 13:40:11 MDT:
KC9NVN>APX199,TCPIP*,qAC,T2MIDWEST:=4217.27N108940.67W#XASTIR-Linux-Freeport,IL

See the TCPIP in the strings? That says that you are injecting your
packets directly into the APRS-IS stream. The APRS-IS network filters
out any copies heard after the initial packet is heard. You will NEVER
see multiple copies of a packet UNLESS something is screwed up. Copies
do end up being seen when i-gates screw up the packets by doing
erroneous character translations, a packet gets corrupted on the air,
or a Kantronics TNC running in KISS mode gets backed up and delays the
packet for more than 30 seconds before injecting it into the APRS-IS.

> There are a reasonable number of stations in the "Stations heard directly by
> KC9NVN", that makes sense. It seems I can hear OK. I agree that I'm hearing
> a fair number of packets and sending them to the APRS-IS (Igate?) OK, but
> shouldn't I transmit at least every once in a while?

According to what we can see, you are transmitting packets once every
30 minutes.

> Sorry if this is an obvious question but I just don't understand.

Duplicate removal... look at everyone else... only one copy of every
packet sent, but if you listen to the RF network, you'll hear multiple
copies of the packet, one for each digipeater you can hear, and
possibly the original packet heard directly from the originating
station.

It's this "clean-up" process that can lead people to believe that they
need LONG paths because their packet was ONLY heard by digipeater XXXX
located 50 miles away, or some other such excuse.

When looking at the APRS-IS stream of information you must always
remember that you are looking at a heavily filtered output stream, and
you can not base any judgements on the total health of the APRS-RF
network on just the information see on the APRS-IS stream.

James
VE6SRV