[aprssig] Bufferless KISS TNCs ?

Matti Aarnio oh2mqk at sral.fi
Tue Nov 10 14:53:46 EST 2009

On Tue, Nov 10, 2009 at 07:16:49PM +0200, (SV2AGW)George Rossopoulos wrote:
> Hi
> There is already the XKISS and smack KISS mode. Packet Engine Supports it
> and you can test it easily.

I don't use Windows environment, sorry.

It took a while to figure out what is "XKISS".   It is better known as
"BPQ CRC", which in reality is just a XOR sum of packet content bytes.
Not a very good checksum at all...

SMACK is using a real checksum on which even 0x00 bytes affect
the checksum result.

There is also Flex CRC (16 bit CRC checksum)

The 6PACK is also interesting in its own way, encoding 3 payload bytes as
4 link bytes, plus a number of control bytes signaling various things.
This kind of encoding is reason, why it can intermix data and control
signals at lowish latency.

> 73
> (SV2AGW) George Rossopoulos

73 de Matti, OH2MQK

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