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[aprssig] Packet routing, path specification.

Robert Bruninga bruninga at usna.edu
Thu Jun 23 01:18:57 UTC 2005


>>> HamLists at ametx.com 06/22/05 7:42 PM >>>
>> That is, that it also means the only thing you will be able 
>> to do with the channel is what your local SYSOP decides
>> you can do.   My experience is that this approach usually 
>> [fails in many areas]...
>
>No such thing.  It does say that you can't define your 
>path (or that if you do, it is ignored)...

Let me re-iterate, Pete's system is an excellent
solution and it will work in many areas where there
are consistent expectations.  Dallas is a good example..
a large APRS density surrounded by very low density
operations and even in those areas, the focus on
communications still pertains to Dallas.  It should work
very well, and I doubt there is any problem setting
up a well defined system.

But this model completely falls apart on the East coast
where I am.  We have probably 1000 users in one
long chain of cities (all one digi hop apart) from
DC, Baltimore, Philly, Trenton, NJ, NYC, Long Island
Connecticut, rhode Island, Massachussetts through
NH and VT to Maine.

Yes, people in Baltimore CITY could concevibly agree on 
the boundaries of a Baltimore net, and so could most of
the denizens of Wash DC city only.  But the problem is
that MOST hams live in the suburbs inbetween,  and fully 
HALF of those in the same area, claim the opposite city as 
their sphere of interest. Ether because of where they work
or school, or play.

There is no such thing as ever being able to define
a boundary of where one particular digi will allow
its users packets to go.  Because half the people
in each SAME neighborhood could care less about the
other city and its comms needs in many cases, and
it is this way for 500 miles and 1000 users between
13 different "sphere's of influence".

In this area, WIDE2-2 is the ideal path because
no matter where one is, he can comunicate
with everyone around him out 2 hops and even if he 
is Far into Baltimore subburbs, but wants to maintain
his association with Washignton, he may do that
easily.  He simply choses the route DIGI1,DIGI2,
etc to get his packets to his area of interest.

So we have to be careful when trying to compare 
"network ideas".   Some ideas work very well in some areas
and different ideas work every well in other areas.  

So I appoligize where I implied that the SYSOP-knows-
all solution just wont work.  It can clearly work well
where you can get ALL digis and ALL sysops to agree
on the settings for each digi and the route each digi
will allow or not.    

What I meant was that it just wont work along the 
congested eastern Seaboard which is my experience 
base.  I am sure it will work very well in isloated 
areas where expectations are consistent and easy 
to define.

I dont want this to a this-net-is-better-than
that-net.  Just recognize that there are better
optimum solutions for diferernt areas.  And lastly
that no matter what a local area decides to do,
it must respond consistently to all mobiles
everywhere.  Or again, the consistency of
APRS as a service for mobiles is lost.

Bob






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