[aprssig] Q: Paths and the D700 and Digipeating in General (LONG)

Tue Jun 7 12:21:00 EDT 2005

Boy, just when you think you have it... another explanation comes along and messes up things...
Bob sure gives easy to understand explanations, but somehow the half life of this knowledge seems to be somewhere around 24 hours.  I think my brain is FULL.   I have long-been digging around the internet and also have the APRS spec [80% over my head so far), but this path stuff is still foggy and I know it is really quite easy.  Archive hunting is fraught with lots of un helpful stuff to sift through.  All explanations on the net seem to assume way-more knowledge about packet than I have (Zero)

I'm trying to undrstand the *basics* of the path designators.   I've  had a D700 for about 2 years and some of this is starting to stick, but... 

I get the WIDEn-n concept, but it is the series of XXXX,YYYY path designators (aliases)  and precisely how they are handled that I have fog.  If there is a clear explanation of just how packet paths are handled, on the net, point me there and forget the rest of this as this may all be handled by one paper or answer...  Here goes.

In excerpt 2 (below), the *Bob* recommends a  D700 digipeater path of:
               Set APRS-UIDIGI to TEMP,WIDE1-1
Now, it seems that the tracker should have a path of only TEMP,
Except Bob says:
               Set pocket tracker to use path VIA WIDE1-1,WIDE2-1

SO.. FIRST  basic UIDIGI stuff:
Will a digi set for TEMP,WIDE1-1 digipeat a packet with _either_ a path of TEMP  *OR*  WIDE1-1   in the first slot?
  I think I am asking ;  Is it the case that a Digi will 'peat a packet with *any* of the alias's (in the currently tested spot of the packet) in its own UI list?

Then, for a station originating packets:
Are the aliases handled only sequentially by digis, left to right?  like this...
With a path of :      XXXX,YYYY
Is it true that this packet will ONLY be 'peated by a Digi with XXXX in its list?  In other words if no XXXX Digi hears it, it dies, forever lost in the ether, even if a YYYY Digi hears it?

Then the XXXX Digi transmits it  (marking XXXX with  *) and only a YYYY digi will then 'peat it?

So, Digis look for the first alias without  * and if it gets a match with *any* in its list it  repeats it?

===  Part two  GATE question  ===
In the HF case (1st excerpt below).  The recommended path 
               GATE,WIDE2-1
means that ONLY a GATE will take this packet off the RF network, right?______
Then, after the GATE gets it, it will only then be digipeated by the true WIDE (assuming it has the WIDEn-n software)?___

  Except,  is this from the HF side *to* 2M or  from 2M to HF -- or does it matter -- ?_____

Moving to (the final) PART 3 a related topic "Call Substitution"
Without this, I believe each Digi that  'peats a packet puts an asterisk (*) in the field of the path designator it "used" ??   Hmmmm  Peter piper 'peats a peck of 'peated packets...

*With* Call Substitution, we will see (within the 'peated packet) a list of calls of the digis that handled this packet, right?  I think the last one will have the *   I look @ the findu raw packets and next hope to follow the q construct information there...'cept I don't really know wht a "client" is...

Ah, what the heck, as long as I'm here...

What is the stuff immediately after my call (T2PS9Y) in the APRS-IS packets on findu:
K9DCI-9>T2PS9Y,WB9WLS*,WIDE2-2,qAR,KH6KI-1:'tZdl,M>/]Steve Wonder Lake IL 145.410   ???
Hmmm  I thought I changed back to .WIDE1-1,WIDE2-1

73, Steve, K;9.D'C,I

==========   EXCERPT #1  =================

Date: Fri, 03 Jun 2005 19:26:27 -0400
From: "Robert Bruninga" 

Subject: Re: [aprssig] HF and the new n-N paradigm, mobile digis

Good questions!

>What would be the recommended path for APRS 
>mobile/portable stations on HF? ... the old way 
>was to use GATE, WIDE ... Would the new way
> be GATE, WIDE1-1?

No, because the special path of WIDE1-1 is for
use by home and fill-in digis only. So better to
use the path of GATE,WIDE2-1. It is still only
a 1 hop path but does not key up home stations.

>Also, is there any convention in place for a standard 
>alias to be used for a mobile digi? For example, ...
>I've got a pockettracker.... to make it back to my car
>DIGI...

Yes, set your D700 to digipeat by using a PC to enable
its UITRACE parameter with the permanent alias of
TEMPn-N. This way, any mobile any time can be used
as a temporary digi, but all the other time, the digi does
not digipeat any normal on-air packets and so does not
add any problems. But is always available.

de WB4APR, Bob

==========   EXCERPT # 2  ================
Message: 9
Date: Sat, 04 Jun 2005 09:50:53 -0400
From: "Robert Bruninga" 

Subject: [aprssig] Mobile Digis (New -N Paradigm)
To: , , "Robert Bruninga"

Message-ID: 
Content-Type: text/plain; charset=US-ASCII

We should add this recommendation formally to the 
New-N Paradigm. This will go a long way towards
common and consistent use of pocket trackers and
other temporary applications:

D700 user's should be aware of these settings:

NORMAL OPERATIONS:
Set APRS-DIGI OFF!

DIGIPEATING A POCKET TRACKER:
Set Tracket to 144.99
Set D700 band B to RX 144.99
Set D700 band A to TX 144.39
Set D700 TNC to RX B & TX A
Set RADIO-TNC-DCD to both A&B
Set APRS-UIDIGI to TEMP,WIDE1-1
Save in a PM just for this application
Set pocket tracker to use path VIA WIDE1-1,WIDE2-1

This will make the pocket tracker use the the full
power of the D700 and with courteous channel 
sharing AND with no interference or congestion
between the tracker and your mobile. Notice that
setting DCD to both is generally not a good idea
for normal operation because it will keep your 
normal posits from going out if you are using band
B. So that is why this should be in a PM all its 
own only used for digipeating the tracker.

ADDITIONAL SETTINGS using a PC:
Set UITRACE TEMP,30

This will cause your D700 to ALWAYS be ready at
any time to act as a temproary digipeater in support
of TEMPn-N routing. SUch as FieldDay.

The question is whether this is saved in APRS mode
or only in packet mode. And if you set it while in a
PM, can it be saved there too? I suspect this only
works in PACKET mode but that is fine for Field Day
or any other temporary net you want to set up.

RESULT OF TEMP mode:
You can use TEMP or WIDE1-1 to digipeat thorugh any
mobile that is in APRS mode and has APRS-MENU-DIGI ON.
And you can use TEMP7-7 as a path for Field Day
via any D700 that is in packet mode or any other time.

Once we all agree to this or some other arrangement,
lets get EVERYONE on board. We can easily 
send a MESSAGE to ALL D700 users by simply using
the GROUP MESSAGE function. All of the Kenwoods
come with the default MESSAGE group of KWD.

Until we get the word out, a good message might be

To: KWD: See new-N settings for D700. Google XXXXXXX

and after we get everyone to a consistent set, then for
special events where you need an instant net on 
a different freq for emergency or special comms then:

To: KWD: SPECIAL, pse support alt-net on 145.01 TNX

or any other uses.. But we need owners to be fully
awayre of the potential of their radios, how to set
them up, and how to use them. THus, I want us all to
debate the final settings for digipeating and agree and
then include it in the New-N pparadigm so that APRS
works consistently everywhere and is flexible and can
respond quickly to emergent needs.

de Wb4APR, Bob

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