[aprssig] Understanding IGATE

[Steve Dimse]

On Jun 16, 2005, at 5:45 AM, Jeremy Bair wrote:

> I have found these options available in UI-View32 but found it  
> strange that APRS-IS does not coordinate IGATEs in a switching  
> configuration to best route messages,

I agree with Pete, what you have to remember is that RF propagation  
is not constant, accounting for all the possible variations would be  
difficult, and more likely to result in missed messages. The original  
design of the APRS IS was to make it as likely as possible that  
messages would be delivered. About the only thing that I would do  
differently now is to have provision for primary and secondary  
IGates, where one IGate could be a hot standby for another. Now the  
choice is to have both active two way IGates (more QRM on RF) or one  
active and the other one-way (requires the backup IGate operator to  
recognize that the primary is down and reconfigure as a two way IGate).

If I understand your problem correctly, this could be the cause.  
There might have only been a one way (RF to Internet) IGate feeding  
the RF packets to the APRS IS and on to findU, but a one-way IGate  
cannot send Internet messages back to RF.

Steve K4HG