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[aprssig] Delayed Packets

A.J. Farmer (AJ3U) farmer.aj at gmail.com
Mon Oct 24 03:43:56 UTC 2005


On 10/23/05, Stan Coleman N0YXV <n0yxv at gihams.org> wrote:
> We have what I think is a unique thing happening in our town. On several
> occasions now we've had packets show up minutes if not hours later after
> they were transmitted. On Saturday we had a mobile that would show up on one

> If my theory is true I think the only fix would be to make sure that all
> IGates in a local LAN area use the same internet server.

A couple of comments:

Regardless of the different servers that the IGATEs are connecting to,
the potential time difference between these servers and their data
reaching the global database is negligible.  Everything is essentially
realtime.

My understanding is that FindU will only "keep" the first packet
received, so even if there was a delay, the duplicates would be
discarded.  However, I think there is a particular dupe check time -
maybe 30 seconds?  I'm sure Steve will comment on that...

This exact topic came up a couple of weeks ago.  I don't recall if the
cause was ever discovered and posted back to the list, but you might
want to search the archives.

A common cause of delayed packets like this can be a digi that has a
malfunctioning or improperly set squelch.  If the squelch is kept
open, then the digi will collect packets in its buffer and dump them
all at once whenever it finally closes.  This could be minutes, or
even hours after the packets are actually transmitted by the
originating stations.

--
A.J. Farmer, AJ3U
http://www.aj3u.com




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