[Xastir] Config file for TM-D710A config script?

[Jarett DeAngelis]

Wow.  I can't say enough how useful this explanation is.  I'm a computer
engineer and you explaining this in terms of OSI is VERY helpful :)

Okay!  So EVERYTHING "speaks" KISS on some level... including things like
PSK-31, Olivia and RTTY?

I think I am going to start making a table of what protocols and
applications work on which OSI layers.  APRS is obviously layer 7 (maybe 6
if you want to get really technical about it)... AX.25 seems like it might
be a mix of layers 2 and 3.

I'm doing digital two ways: one, with my Kenwood TM-D710 (I don't
particularly care how I get this done with the exception that I like the
AX.25 network interface way of doing it, but I don't know how to treat this
radio like an AX.25 interface), and the other with a laptop running
soundmodem and my Wouxun KG-UVD1P HT.  I've actually gotten soundmodem
working before in AX.25 network interface mode, the only problem being that
I had a bear of a time getting the stupid thing to trip PTT.  I think I've
finally solved that issue with a circuit board I built.  We shall see this
evening.

Eventually I'd like to be able to run all digital modes on both rigs.  One
thing at a time, though :)
On Jul 3, 2011 7:01 PM, "James Ewen" <ve6srv at gmail.com> wrote:
> On Sun, Jul 3, 2011 at 3:06 PM, Jarett DeAngelis
> <jdeangelis at alumni.nd.edu> wrote:
>
>> All right then, still more confusion!
>> I thought TNCs operated in three modes:
>>
>> KISS, which is "barebones" and allows application software to manage how
the
>> TNC interprets bits,
>>
>> Serial, which makes certain assumptions about how data is handled (kind
of
>> like a modem for phones),
>>
>> AX.25, which creates a protocol specific network adapter on the OS level
>> that many applications can access (useful for Xastir and IP applications)
>>
>> Am I wrong here?
>
> You're a little mixed up...
>
> The link to the packet radio primer takes you off on a bit of a
> tangent. It does have a bit of information relevant to your query, but
> it takes you on a rambling tour of BBSes and Nodes, etc.
>
> All TNCs and packet radio are serial devices. They send data one bit
> at a time over the air. You also talk to them from the computer in a
> serial manner as well, whether using the serial port, or a USB device.
>
> AX.25 is a protocol definition, it defines the "language" that the
> TNCs speak to each other over the air in a serial stream..
>
> KISS is a manner of framing the packets that uses AX.25 to send data
> over the air in a serial manner.
>
> You can't do KISS without using AX.25... you can't do AX.25 without
> sending data via a serial data stream over the air.
>
>
> You're more likely thinking of things at a higher level...
>
> You can run a TNC in KISS mode. That leaves all the dirty work of
> building the packet frames to be sent, and decoding the packet frames
> when the are received up to the controlling program. The program has
> to build the complete frame, including the header and other
> information. It takes more work to get the packet out, but the program
> has ultimate control over what goes out over the air.
>
> The next level up is sometimes called "text mode". Here all that the
> program has to do, is present the information to be sent out over the
> air to the TNC. The TNC looks after building the frame. When the
> packet is received, the TNC pulls the user data out of the incoming
> data stream, and presents that to the user.
>
> There's also another level up where the radio has APRS smarts built
> into it, where the data is deciphered and displayed on screen for the
> user rather than having "raw" data presented. The Kenwood and Yaesu
> rigs are examples of this.
>
> Wikipedia gives a fairly concise rundown of the workings of AX.25.
>
> http://en.wikipedia.org/wiki/AX.25
>
> It might help to get a basic understanding of the OSI communications
> model as well...
>
> http://en.wikipedia.org/wiki/OSI_model
>
> Some of what you are talking about (serial communications) is at layer
> 1 the physical layer, some (KISS) at layer 2 data link layer whereas
> the APRS interfaces of the Kenwood and Yaesu radios is up at layer 7
> the application layer. (This doesn't exactly fit the full OSI model,
> but it gives you a basic concept of how each layer builds upon those
> below it).
>
> Think of it this way... APRS modes in the Kenwood and Yaesu radios is
> like riding in a limo with a chauffeur. Drop down to plain old text
> mode, where the packet contents get delivered to you, and you're now
> the one driving the car. Back down to KISS mode, and we've just handed
> you a big box of parts where you get to build the car before you get
> to go for a drive. If you want to drag AX.25 into this analogy, we'll
> have to give you some chunks of steel and CAD drawings of what the
> parts need to look like for you to build the car.
>
> Generally the deepest we go is into KISS mode where the packet frames
> have to be built up and decoded within the program accessing the TNC.
> encoding and decoding the bits into audio, keying the radio, carrier
> detection and the like is all looked after by the TNC hardware.
>
> --
> James
> VE6SRV
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