[aprssig] Gawd This APRS Path May Reach Mars!

Bill Herrmann bherrman at spro.net
Tue Feb 1 23:50:55 EST 2011


At 07:19 PM 2/1/2011, Eric Hansen wrote:
>Can someone give me a run-down on the n-N pathing? wide1-1,wide2-1 
>means hop from a fill in repeater, two from a mountain top?

Close
wide1-1 means 1 hop from a fill-in digipeater or 1 hop from a mountain top
wide2-1 means 1 hop from a mountain top
The total path means two hops total. (The 2-1 is used so that a 
fill-in won't touch it.)

>  What does that guy's path mean?

That he doesn't understand paths? (sorry, had to be said)

Think of it this way:
For a wideX-Y the X originally indicated how many hops you started 
with and Y indicates how many hops you have left. Each wideN 
digipeater is supposed to decrement the hops left and the last digi 
is supposed to mark it as used.

One of the common misunderstandings is how a TNC uses the path. If 
you looked at a path like digiA, digiB, digiC each digi has to be 
used up in sequence. If digiB hears it directly it will not digipeat 
the packet. It will only digipeat it if the digiA portion of the path 
has been marked as used.

>WIDE1-1,WIDE2-2,WIDE3-3,WIDE4-4,

A path like this is essentially the same as wide10-10. Ten hops is 
bad enough, but it is 10 hops in all directions. With mountain top 
digis we're talking abuse of thousands of square miles.

Bill





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