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[aprssig] Fixing older KPC-3 Duping Digis!

Cap Pennell cap at cruzio.com
Wed Aug 31 19:44:02 UTC 2011


Still better, I think, for old digipeater Sysops to just add UIDigi WIDE1-1
in the Kantronics version KPC3-3F427265-8.2 TNC as previously recommended. 
http://www.aprs.org/kpc3/kpc3+82WIDEn.txt 
In practice, this certainly works well enough.
In California, we build our fixed VHF digi network to support a user's path
of WIDE1-1,WIDE2-1 (or less) from anywhere.  A digi that won't operate
packets addressed via WIDE1-1 isn't of much use.
73, Cap KE6AFE

> -----Original Message-----
> From: aprssig-bounces at tapr.org [mailto:aprssig-bounces at tapr.org] On Behalf
Of
> Bob Bruninga
> Sent: Wednesday, August 31, 2011 10:55 AM
> To: russo at bogodyn.org
> Cc: 'TAPR APRS Mailing List'
> Subject: [aprssig] Fixing older KPC-3 Duping Digis!
> 
> > Yes, it would.
> > What format and means do you suggest?
> 
> This is the best news since 2004 New-N Paradigm!
> 
> * In 2004 we standardized APRS on WIDEn-N (including W1-1,W2-1)
> * In 2005 We standardized Digi localinfo Beacons to include
>   - Digi info format (W2, SSn-n.) (or W3, etc)
>   - Local Freq Objects for Voice, IRLP and Echolink, etc
> * Now, in 2011 we solve the old KPC-3 problem!
> 
> Instead of the "W2, SSn-N..." format for the digibeacon, we now suggest
for
> these old KPC-3's to use a new format "W2-2 SSn-N...".  Where the "W2-2"
is
> the Key to mean "Do not use W1-1 in this area.  Use only W2-2 (or W3-3 if
> ok).  If every old KPC-3 with the dupe problem used this standard beacon,
> then we can now educate people that when they see that specific "Wx-X..."
> nomenclature that it means to only use that path because that digi is a
> duping KPC-3. SO basically we are changing the "W2" to a "W2-2" as a
subtle
> but standardized way to convey this info to users (or W3-3 in some areas).
> 
> Remember, under the 2005 http://aprs.org/localinfo.html recommendations,
> what comes out of a digi to its immediate users are:
> 
> 1) The digi beacon every 10 minutes DIRECT
> 2) The digi beacon every 60 minutes via 2 hops *(see below)
> 3) Local FREQ object(a) every 10m direct
> 4) Local FREQ object(b) every 10m direct
> 5) Local Freq object(c) every 10m direct
> 
> Problem is that my guess is fewer than 1 in 3 digis ever even upgraded to
> the 2005 Local-Info initiative (beacons 3,4,5 above).  But this is a good
> time to do all of that.
> 
> Would that work?
> 
> The goal everywhere is that if your radio has been on for 10 minutes, your
> APRS radio should capture all the local info of value, the DIGI, Voice,
> Echolink and IRLP or other info.
> 
> NOTE:  I think there should be two options for the DX beacon (#2 above).
As
> shown, it is for large sparse networks like New Mexico or something where
> you want to see the overall network of digis (few people out there).  But
> for dense areas like back-east, I think making the DX beacon every 30
> minutes is no more total packets but then at least every 30 minutes lets
you
> see the next digi beyond the one you are currently in.
> 
> Back east, waiting an hour for that info is too long to wait.
> 
> Bob, Wb4APR
> 
> 
> 
> -----Original Message-----
> From: Tom Russo [mailto:russo at bogodyn.org]
> Sent: Wednesday, August 31, 2011 1:17 PM
> To: Bob Bruninga
> Cc: 'TAPR APRS Mailing List'
> Subject: Re: [aprssig] APRS talk in Los Alamos?
> 
> On Wed, Aug 31, 2011 at 01:10:21PM -0400, we recorded a bogon-computron
> collision of the <bruninga at usna.edu> flavor, containing:
> > Tom,
> >
> > EXCELLENT explanation!
> >
> > Now would this problem go away if people used the WIDE2-2 path in that
> area
> > instead of WIDE1-1,WIDE2-1??  I think so, because then the DUPE filter
> would
> > work on the 2nd hop?
> 
> Yes, it would.
> 
> > If this fixes it, then our goal would be to get ALL such OLD KPC-3's to
> have
> > a BEACON that says something like: "Use W2-2."  Especiall in an area
whre
> > most of the TNC's have this problem?
> 
> The recommendation to use W2-2 is in fact on the web page of the club that
> maintains the digis (www.urfmsi.org).  I agree that it would be a good
idea
> for those digis to have some kind of standard beacon that would be
> easily recognized by users.  What format and means do you suggest?  I
could
> possibly pass it on to the fellow who maintains the digis.  It might be
some
> time, though, before it gets implemented.
> 
> > -----Original Message-----
> > From: aprssig-bounces at tapr.org [mailto:aprssig-bounces at tapr.org] On
Behalf
> > Of Tom Russo
> > Sent: Tuesday, August 30, 2011 8:18 PM
> > To: TAPR APRS Mailing List
> > Subject: Re: [aprssig] APRS talk in Los Alamos?
> >
> > On Tue, Aug 30, 2011 at 05:05:25PM -0600, we recorded a bogon-computron
> > collision of the <ws5n at wildblue.net> flavor, containing:
> > > <html><head><meta name="Generator" content="PSI HTML/CSS Generator"/>
> >
> > [you might want to adjust your mail program to send only plain text
email
> to
> > APRSSIG --- those of us using old-fashioned text mail programs get to
see
> > all the HTML markup, which I've hand-edited out in my reply]
> >
> > >While there I hope you can monitor the APRS traffic around the city.
> > &#160;When I drive in to Albuquerque, I start hearing "MY POS" repeats
> > sometimes three or four times each time I beacon. &#160;I have heard it
as
> > much as 7 times! &#160;I am running WIDE1-1,WIDE2-1 in the mobile.
&#160;I
> > have my suspicions as to what is happening, but I don't have the
expertise
> > to analyze the situation and make recommendations. &#160;I'd love to
hear
> > your take on it, if you see the same behavior.
> >
> > That's because all the nearby digis are ancient KPC-3 TNCs with old
> > firmware,
> > with broken handling of WIDEn-N:  they fail to mark the final hop as
used,
> > so if WIDEn-N were implemented normally the path you are using would
only
> > be a one-hop path:
> >
> >    first transmit:  WIDE1-1,WIDE2-1
> >    First digipeat:  LAMOSC*,WIDE1,WIDE2-1
> >    First digipeat(2):  SANDIA*,WIDE1,WIDE2-1
> >    First digipeat(3):  CAPILA*,WIDE1,WIDE2-1
> >    First digipeat(4):  ELKMTN*,WIDE1,WIDE2-1
> >     (etc. for every digi that happens to hear you)
> >    End of line, because nobody will digipeat this (WIDE1 is showing as
the
> >     first unused digi, and nobody will do anything with that).
> >
> > SO, the work-around is that all of these digis have a workaround in
place:
> > MYALIAS is set to WIDE1-1, with all the problems that go with it ---
> > notably,
> > no dupe checking on the first hop.  So you get THIS mess instead:
> >
> >    first transmit:  WIDE1-1,WIDE2-1
> >    First hop:  LAMOSC*,WIDE2-1
> >    First hop(2):  SANDIA*,WIDE2-1
> >    First hop(3):  CAPILA*,WIDE2-1
> >    First hop(4):  ELKMTN*,,WIDE2-1
> > and then
> >    Second hop:   LAMOSC*,SANDIA*,WIDE2
> >    Second hop:   LAMOSC*,CAPILA*,WIDE2
> >    Second hop:   LAMOSC*,ELKMTN*,WIDE2
> >    Second hop:   SANDIA*,LAMOSC*,WIDE2
> >    Second hop:   SANDIA*,CAPILA*,WIDE2
> >    Second hop:   SANDIA*,ELKMTN*,WIDE2
> >    and so on and so on.
> >
> >
> > That is, if you use WIDE1-1 you're no better than the Bad Old Days of
> > RELAY,WIDE, thanks to outdated hardware with outdated firmware.
> >
> > The KPC-3's are all donated hardware from WA5IHL who used to maintain a
> > large
> > number of normal packet nodes with them, and repurposed them in the
early
> > days of APRS.  It is not reasonable to expect that they'll all be
replaced
> > in any sort of short order with more modern hardware/firmware, so we're
> > stuck
> > with the local advice NOT to use WIDE1-1,WIDE2-1 in the central New
Mexico
> > area --- just use WIDE2-2 so that all dupe checking is actually done
> > properly.
> > With WIDE2-2, no ping-ponging is possible, you get fewer "MY POS" beeps
> > on your D7X0, and the channel gets less congestion.
> 
> --
> Tom Russo    KM5VY   SAR502   DM64ux          http://www.swcp.com/~russo/
> Tijeras, NM  QRPL#1592 K2#398  SOC#236
> http://kevan.org/brain.cgi?DDTNM
>  "One man alone can be pretty dumb sometimes, but for real bona fide
>  stupidity, there ain't nothin' can beat teamwork." - Edward Abbey
> 
> 
> 
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