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[aprssig] New n-N success in North Carolina

Jason Winningham jdw at eng.uah.edu
Sat Feb 12 19:40:51 UTC 2005


On Feb 12, 2005, at 9:58 AM, Wes Johnston wrote:

> I kindly disagree with this.... In this example you take my packet and 
> alter it
> at the point of entry into the network.  From there, every digi that 
> hears my
> packet would then digipeat it that max_allowed_hops.

Not quite;   I alter your packet by decrementing the hopcount at least 
one.  If you're asking for more hops than the I think appropriate for 
the area served by my router, I'll decrement by more than one.

> THis is the same a 2nd
> hand source routing.... let's call it proxy source routing.

No, this is exactly identical to the IP TTL field.  I called it hop 
count because that's what it is; TTL is a misnomer on the part of IP, 
because time has nothing to do with it. (Yeah, I know it takes time to 
transmit that many hops, but that's incidental.)

> Catching the maxhops would be the responsibilty of the first digi in 
> the chain.

No, the first router (digi) in the chain would have the first shot at 
it.  Every router would have the option of applying it's own 
max_hop_count, so a distant rural router could chop an 8 to a 5, let 
the packet hop once to a city, then a big city router could reduce it 
from 4 to 2.

> Like Bob's "trap out" method it would put me (as a digi owner) in a 
> position of
> depending on other digi owners to control what my digi is subjected 
> to.  I
> strongly feel that each digi should be responsible to determine it's 
> own
> limits.

No, I'm putting the power to do determine what the router (digi) will 
handle _exclusively_ in the digi operator's hands, instead of the hands 
of the client operator.


> I think a better model would be to allow *each* digi along the way to 
> decide
> what was the max that *it* would digipeat.  It would either digi the 
> packet or
> not, but would not alter it for the sake of other digipeaters.

This is more or less what we've got now, with the aliasing of W7-7 and 
W6-6 to effectively drop them, if I understand Bob's plan correctly.  
What I'm talking about is accepting that RELAY,WIDE7-7, tag the 
digipeated bit on RELAY and rewriting the WIDE7-7 as WIDE7-2 (assuming 
my router's max_hop_count is 3).

> if y > x then
> 	y=x    ' trap the lids who would like to run wide3-7 or wide7-15
> end if

If I follow your example correctly, we're saying the exact same thing.  
I simply left out the WIDEn-n terminology in favor of hop count a) 
because it's simpler, b) it is the terms we should be thinking in, and 
c) it's the concept we should be shifting toward.

-Jason
kg4wsv





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