[aprssig] APRS "text messaging" over long distances

[Stephen H. Smith]

ik7565 at verizon.net wrote:
> Does every iGate put my message out 

NO
> or are the iGates smart enough to know
> where we're located and only put out a message if it heard the recipient?
>
> Thanks, Ian N8IK
>
>   
YES.   Each igate maintains a list of stations recently heard locally on 
RF.  "Recently" usually means somewhere between 30 minutes and two hours 
or so.  "Local" may mean direct or it may mean within one digipeater 
hop.    Both are at the discretion of the igate sysop.  

The igate monitors all messages from everywhere passing through the APRS 
Internet system.   When it sees one addressed to a call matching one in 
it's "recently heard" table, it captures it and transmits it out to RF. 
  Note that even even when an igate is connected to an Internet server 
filter port that limits the geographic area of POSITION reports, it will 
receive and act on MESSAGES from anywhere.



Stephen H. Smith    wa8lmf (at) aol.com
EchoLink Node:      14400    [Think bottom of the 2M band]
Skype:              wa8lmf
Home Page:          http://wa8lmf.com

"APRS 101"  Explanation of APRS Path Selection & Digipeating
  http://webs.lanset.com/wa8lmf/DigiPaths

Updated Rev H APRS Symbol Chart
  http://webs.lanset.com/wa8lmf/miscinfo/APRS_Symbol_Chart.pdf   

New/Updated "Rev H" APRS     http://webs.lanset.com/wa8lmf/aprs
Symbols Set for UI-View,
UIpoint and APRSplus: