Re: Igates and their use of digi paths

Greg Depew

See below

Greg KB3KBR Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: Lynn Deffenbaugh <kj4erj@...>
Date: 6/19/20 09:31 (GMT-05:00)
Subject: Re: [APRSISCE] Igates and their use of digi paths

Can you give a more complete description of what all is involved?

KB3KBR-11 is what station?  Software, TNC and radio please.

11 is a Yaesu Ft1d

Same for -4 (a WIDE1-1 digi) 

4 is a fill in digi , TinyTrak 4 with GPS and and FT 8800 in a go box programmed to only respond to Wide1-1 and it's own callsign 

Same for -1 (presumably a WIDE2 digi)

1 is APRSIS32 via sound card Signal link into an Ftm 350and is an igate and digi that responds to Wide1-1 and Wide2-2 

Same for the IGate and please include callsign-SSID with the other 3 pieces of the puzzle.

And some idea of who can copy who directly.  Can -1 copy the IGate directly or does the IGate need the boost from -4 to get to -1?  

1 is the igate, 4 is my mobile fill in that I'm using to get 11 back to the igate 

You've already mentioned that you can't hear -1 indoors, but only -4.  Can you copy the IGate indoors?  

When I'm at work inside our 911 center our grounding halo blocks just about everything. 4 is sitting in the truck in the parking lot and can hear 1 and 11. 11 can only hear 1 if it's out side and its iffy if 1 can hear 11 without either holding the antenna in the or more power.

If not, then can we assume the IGate is actually remote from your QTH, but -1 is local?

First, you don't really want to respond with the "same path as received".  You'll need at least to reverse the path and remove the used bits.  (Yes, programmers tend to be as literal as the computers that we work with all day).

And then you have to decide whether you want to use the reversed aliases from the incoming path or the explicit digipeaters.

Then you realize that aliases mean more than just WIDE1 and WIDE2 in some areas.  So, what's an alias?  (see PS below).

And finally you realize that some digipeaters don't insert there callsign into the path, and others might remove the alias that they consumed, and yet other digipeaters completely replace the original path with their own callsign and what's left of the alias.

So it really is unfeasible if not impossible to generically determine the "reverse" path to use for a message response.  And I didn't even mention the issues that come up with "Proportional Pathing" where a station rotates through different paths for different packets, so which one do you use?  And don't say "the one that brought the inbound message", because the first message gated to a station may be an unsolicited one from some -IS-remote station.  It might not be a reply that we're gating.

But if you provide the information requested above, we might be able to assist in setting a good path for your IGate to use, or provide an explanation as to your issue of receiving packets while indoors.

Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32

PS.  See the Configure / Aliases menu on your IGate (presuming that you actually run APRSIS32 on the IGate) and check Configure / Aliases / Accumulate if it isn't already checked.  That will cause it to start populating the Configure / Aliases / Possible over time.  If you have Accumulate checked, you should also get a bunch of new Alias* trace logs that, if enabled, can provide an insight into what APRSIS32 is doing with Alias detection.

Aliases listed in Configure / Aliases / Known are not counted against the "used hop count" for determining "local" as well as putting the used hop count in the packet scroller.  They also won't show up as the digipeater or IGate which delivered the packet to the IGate or instance.

So, if you're using Configure / Scroller / IGate/Digi to see the station that you copied a packet from and are seeing some local alias (WIDE is pre-defined in Known, IIRC), then add that alias via Configure / Aliases / Known / New (or select it in Possible if it is there), and make it a known alias so that APRSIS32 will see the digipeater before the alias to put into the first column of the packet scroller.

Oh, and the timestamp beside the aliases in both Known and Possible are the time since that alias was detected in any processed packet.

Finally, the Configure / Aliases / Unused-0 shows those detected aliases that were seen without a used bit and without a -SSID meaning the remaining hop count was zero but yet the alias was not marked used.  The source callsign-SSD of the packet containing such an alias as well as the detected station type of that callsign-SSID are included so that you can go back to the raw packets and see what is going on. 

Consider the following packets with trailing unused -0 aliases:

MDAAOC-1>SYPY8R,N3KTX-2*,MD2,qAR,W3KIT-10:'hAJl o/]147.075MHz T107 +060de W3AAC=
KB6YTD-3>APN391,K6CDF-3*,NCA1,qAR,K6CDF-5:!4039.53N112313.17W#PHG4810/ Fill-in
K7D3>APTW14,K8COP-3*,MI3,qAR,DANSVL:!4352.60N/08550.95W_ KD8EHO Baldwin Airport, Lake Co., MI. Weather
UNION>APN391,W7MOT-3*,AZ2,qAR,N7SU-10:!3424.86NS11224.25W#PHG7830/SAR DIGI  JEEP POSSEPRESCOTT  KB6TWC    7900FT
OH64K-4>APRX29,OH9RDB*,TRACE2,qAR,SK2DR-10:)Ahma!/-#xQTOEe-{3CQRP station 129 17241 51.2C 11.85W 11.96V 50%|!/.(.]!Q!!!!"1|
K3MLS-9>S9TX7Q,W3UD-3*,WIDE1,WIDE2-1,qAR,W2MMD-13:`gV' Sak/]"5f}146.985MHz T100 -060Monitoring 146.520=
IW9GDC-6>APNBCN,IR8DA*,WIDE1,WIDE2-2,qAO,IW9GDC-10:!3808.50N/01530.31Er/A=001400Next Generation Beacon 50.006 MHz JM78SD
F5VO>APRS,F8KSM-3*,WIDE2,qAR,F1EFQ-10:Software: UISS 5.4.2
CDS>APN391,WALSH*,BORGER*,WIDE4,qAR,KD5ROK:!3426.19nN10013.37w#PHG7430/W3,WTX DE NL7C nl7c@...

The real question is did the originating station do it or did the digipeater not put the used bit (*) on the used up path component?  Only people local to those stations and/or digipeaters will ever know for sure...

On 6/18/2020 11:06 PM, Greg Depew wrote:
Is there a way for APRSIS32 to respond to messages through the same path as received? What I'm trying to do is get a message back from the internet through my fill in digi. 

I send a message to Wxbot from KB3KBR-11 and -4 digipeats it and then -1 digipeats it too. If I'm outside of the building I'm in i can hear -1 direct and get the message, if I'm inside I can't hear anything except -4. 

What I'm looking for is a way for -1 you send the message back through -4 so -11 can hear it. 
-4 is a fill in only responding to Wide1-1 and it's own callsign. 

Greg KB3KBR Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------
From: Justin Cherington <huntjlc@...>
Date: 6/17/20 09:22 (GMT-05:00)
Subject: Re: [APRSISCE] Igates and their use of digi paths

hi Arnold, Lynn got me all set with his reply. 

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