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[aprssig] Fixing older KPC-3 Duping Digis!

Tom Russo russo at bogodyn.org
Wed Aug 31 19:48:27 UTC 2011


On Wed, Aug 31, 2011 at 12:44:02PM -0700, we recorded a bogon-computron collision of the <cap at cruzio.com> flavor, containing:
> 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.

My bad.  It's the UIDIGI, not MYALIAS that these  KPC-3's in NM use as WIDE1-1.
The ping-ponging issue, however, is still the problem that shows up, because
UIDIGI doesn't do dupe checking.

Dupe checking only happens with UITRACE and UIFLOOD, and these models of
KPC-3 have busted firmware that do the wrong thing with WIDE1-1 when caught
by those parameters instead of UIDIGI.

> > -----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
> > 
> > 
> > 
> > _______________________________________________
> > aprssig mailing list
> > aprssig at tapr.org
> > https://www.tapr.org/cgi-bin/mailman/listinfo/aprssig

-- 
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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