"Andy Knitt" wrote in message
...
Hello Everyone,

I'm very new to packet radio/digital communications and am trying to climb
up the learning curve too fast. It hurts :-) My question is: What
protocol/mode will give me the best data throughput using 9600 baud packet
on VHF or UHF?

Earlier I responded with information about RadioMirror, the multicast
protocol for terrestrial packet that offers truly outstanding
throughput... - But Andy may prefer a connected protocol. In that case,
FlexNet's AX25 stack will give him the best throughput, leaving traditional
AX25 and IP systems in the dust.

A standard TNC has close to 100 different parameter settings that influence
how well the TNC communicates with the computer over the serial link, and
how it performs on the air when hooked up to a radio. Even experts are
sometimes confused by some of the more esoteric link parameters, so many of
these are left at factory default values that are not what you could call
"optimum" but rather represent a compromise.

FlexNet takes full control of all of those link parameters, adjusting them
on a dynamic, minute to minute basis for optimum throughput. With
traditional systems, you painstakingly adjust the TNC parameters once
(static parameters) and hope that it will not be too inefficient. With
FlexNet, the parameters are watched and adjusted on a minute by minute basis
(dynamic parameter settings controlled by the software's A.I.) so that at
any given minute, your TNC is perfectly adjusted to the conditions it finds
with a connection.

End result? Significantly better throughput than any other connected mode
protocol available to hams.

You have to enter your callsign, your data rate and your TXDELAY... All
other parameters are controlled by the FlexNet A.I.. (Artificial
Intelligence) It's like having a little TNC expert hiding in your computer,
who constantly, expertly adjusts your TNC for you as you operate. This type
of software is referred to as an "Expert System", and is the only software
of this type that is wrtitten for hams. (That I am aware of.)

Over a good RF path, FlexNet will send up to seven 256 PACLEN packets at a
time. (Per key-up of the Xmitter) which gives it a data stream almost as
continuous as RadioMirror!

That's nice, but this is even better: When the link conditions deteriorate
(static, other traffic, etc. ) then FlexNet will "automagically" back off on
its radical TNC parameters until it no longer experiences retries, thereby
giving you the maximum possible throughput under ANY operating conditions,
good or bad - All the time!

When conditions improve again, FlexNet notices within a few minutes and will
again open up the TNC parms "like a hose" to give you the very best
throughput under whatever operating conditions the software encounters.

You can run IP over FlexNet of course, but the increased overhead will slow
you down a little. If you don't have a specific need for it, you will be
better off without it.

To find info about FlexNet, look under "Packet Software" in USPN's "Links"
page, and see the Flex32 tutorial in our "Turorial" section.

Good Luck! RadioMirror and FlexNet are your two best options for maximum
throughput at 9.6kb.

Let us know how it goes!

Charles Brabham, N5PVL
Director: USPacket.Net
http://www.uspacket.net