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[aprssig] EchoLink APRS-IS Ojbects Mothballed

Tim Cunningham tim_cunningham at charter.net
Fri Jul 24 04:18:58 UTC 2009

There are a couple of servers like the callbook server that come to mind 
where you query the server for information and it responds. With this 
concept in mind, it might be worthy to devise an Echolink server to query 
information on say 3 available Echolink servers in the requesters immediate 
area. This avoids overloading the network by constant dribbling of the 
entire database, except in instances where the user is sending an action to 
the server to request a list of Echolink server objects in the area of the 

Think of it as an on demand system where the user requests information in 
their specific area, the server sends an ACK back to the requester to stop 
the redundancy, and also transmits the Echolink Object back through the path 
of the requester until the ACK is fulfilled. This allows all in the area of 
the requester to see the available Echolink Objects as well. No more 
bandwidth is utilized than what is sent on demand. The requester hopefully 
gets the data as well as other listeners in the return path of the 
requester. This method should not flood the entire network by keeping the 
requested data local to the requesters digi path and IGate. The down side is 
the requesters local IGate must allow objects to pass back through the RF 
path when dealing with filtered ports on the APRS-IS. Unless the IGate's 
that use filtered ports modify their filter, these object packets could be 

Tim - N8DEU
Decatur, Alabama

----- Original Message ----- 
From: "Lynn W. Deffenbaugh (Mr)" <ldeffenb at homeside.to>
To: <bruninga at usna.edu>; "TAPR APRS Mailing List" <aprssig at tapr.org>
Sent: Thursday, July 23, 2009 4:38 PM
Subject: Re: [aprssig] EchoLink APRS-IS Ojbects Mothballed

> Robert Bruninga wrote:
>> This item-in-message has been on the requested-features list of
>> APRS1.2 for about a year now..  It is the only reliable way to
>> get a random remote OBJECT back through an Igate into a specific
>> area.  www.aprs.org/aprs12.html
> So Bob, you're tell me that if I end up doing an APRS message queriable 
> EchoLink server and if I generate Item-In-Message format responses, I 
> might be the first to actually use the feature?  Do you know if the 
> D7/D700 (both doubtful) or D710 (maybe?) or any other APRS client in the 
> world actually parses this correctly?  Any chance for an Object-In-Message 
> format using something other than the ) as the leading character?  That 
> way I could continue to keep the ddhhmmz timestamp of last update from 
> EchoLink in the object.
> I'm even willing to sacrifice putting the <location> string at the end of 
> the message in order to make room for the {ack and message prefixing 
> overhead!
> Lynn (D) - KJ4ERJ - Still hoping to find a use for the code!

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