[aprssig] APRS-IS Duplicate Packets

Matti Aarnio oh2mqk at sral.fi
Tue May 4 08:38:51 EDT 2010


On Tue, May 04, 2010 at 06:25:44AM -0500, Jason KG4WSV wrote:
> On Tue, May 4, 2010 at 4:06 AM, Matti Aarnio <oh2mqk at sral.fi> wrote:
> >
> > Essentially for duplicate lookup hashing and subsequent comparison one
> > really needs to ignore all 0x20 bytes at the end of the packet.
> 
> No, you don't.  Pete is absolutely correct, you do not modify the payload!

I do not modify PAYLOAD.  I modify comparison rules.

> It is ridiculous to say that you need to screw up a packet just
> because some other system may have already screwed it up.
> 
> If packet payloads are being modified, the correct solution is to find
> out what system is (incorrectly!) modifying them and fix it.

And what you do in case the culprit is closed-source product whose maker
no longer exist?   Fix by sledgehammer?

Or like the last version of UIDIGI?  Abandonfirmware, no sources.

There is definite reason why I have begun to hate "free of charge,
but no sources published" type of firmwares.  WHEN bugs are found,
hardware with such firmwares are unfortunately "fix by sledgehammer".

It took me months of searching, but I did find eventually KISS firmware
sources for TNC2.  No such luck with any digipeater sources.

> -Jason
> kg4wsv

73 de Matti, OH2MQK




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