[aprssig] [APRSSIG] Universal Messaging

[Pete Loveall AE5PL Lists]

> -----Original Message-----
> From: Magnus
> Sent: Tuesday, October 28, 2008 10:42 AM
> To: TAPR APRS Mailing List
> Subject: Re: [aprssig] [APRSSIG] Universal Messaging
> 
> Lynn W. Deffenbaugh (Mr) wrote:
> > Oh, and an IGate operator can also configure specific call signs to
> > ALWAYS gate from Internet to RF, but this feature should be used with
> > caution due to the possibility of saturating the local RF with data
> that may or may not be relevant.
> 
> Perhaps the default for an IGate should be to hold all messages *until*
> an RF node is heard, and then go ahead and release the message.
> 
> That would certainly keep unnecessary traffic off the local RF.

I think you misunderstood what Lynn was saying in his last post.  He was talking about the ability of some IGates to be configured to pass -all- packets that meet certain criteria (sender's callsign prefix matches VK2 for instance) to RF.  As Lynn pointed out, this can easily lead to saturation of the local RF frequency.

Lynn's post regarding how and when -messages- are gated to RF is correct and, for the most part, the gating of messages does not cause RF saturation since the receiving station must have been heard "recently" on RF before a message is gated to RF.

APRS is near-real-time and both the RF and Internet networks rely on the fact. It is important that no store-and-forward operations occur on the APRS network.  It is up to the sender to retry their message periodically instead of random devices (IGates for instance) storing packets for later transmission.  This ensures that loops, delayed reports, etc. do not occur.

Hope this helps.

73,

Pete Loveall AE5PL
pete at ae5pl dot net