[aprssig] Appalachian 9600 baud KA node Backbone

Steve coupaydeville at gmail.com
Thu Jul 20 19:37:57 CDT 2017


I assume you have access to KA Node hardware already, as otherwise it seems
that the Rpi would be the way to go.

As far as Level 4 is concerned, the only thing I would consider would be
TCP. Even at 1200 Baud.

Back in the early 90's the Segmentation feature came out for NOS and NET.
This allowed long packets in connected mode. Basically you were sending
1024 octet frames, but they were sent as four 256 octet segments.

The advantage was, that the TCP/IP header (what is it? 40 bytes?) was only
sent in the first segment, thus giving you great throughput on the
backbone. Obviously you didn't want more than two nodes in the link, and
you needed different frequencies for each hop.

The second neat thing, was dual band antennas. One Node was on UHF, the
other on VHF. So you could be ACK'ing away on one freq, as the data flowed
on the other.

This was all about the time the hobby collapsed though. I'm not sure how
much of the Connected mode Segmentation documentation still exists.

73/Steve
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