[aprssig] RE: APRS Message Idea

Curt, WE7U archer at eskimo.com
Fri Mar 4 10:29:07 CST 2005

On Fri, 4 Mar 2005 dick at kb7zva.com wrote:

> > I thought IGATED outbound objects were supposed to be tagged with TCP as a
> > pseudo path element, and other IGATES wouldn't gate them to the net to prevent
> > loops?  If this is the case, then FIRENET objects gated to RF would not have
> > been gated back into the APRS-IS.
> >
> > Wes
> > --
> Good question... I'm not sure if that applies to all objects or how the various
> end-user programs handle it. Loops? Duplicates are handled fine on the current
> APRS-IS servers (javAPRSSrvr). That shouldn't be a problem. I'm sure someone
> will have the answer. I got a little nervous when I was told that some programs
> could over-ride the tags like TCP and TCPXX to allow gating.

Anything gated -> RF ends up with a third-party header prepended to
it which has the igates callsign in it and TCPIP in the path.  Going
the other way, anything that has TCPIP in the path doesn't get gated
back to TCPIP 'cuz it's already been there.

As far as overriding tags, do you mean when gating -> RF?  That is
only on a case-by-case basis, with the igate operator having to put
in the specific object/item name or source callsign for the packet.
In other words, the igate operator does due diligence to make sure
that only proper things are gated through.  They wouldn't want to
open it up to just anything.

Curt, WE7U.   APRS Client Comparisons: http://www.eskimo.com/~archer
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