Re: A puzzled maintainer with questions regarding

["M.Baris Demiray" <barisdemiray () gmail com>]

Hello,

On Mon, Feb 7, 2011 at 12:21 AM, Guy Harris <guy () alum mit edu> wrote:
> On Feb 4, 2011, at 12:25 AM, M.Baris Demiray wrote:
>
> > In fact this is not what STANAG 5066 Annex H "Implementation Guide and
> > Notes" section suggests. According to this section and the tests held
> > by DRA (Defence Research Agency),
> >
> > 1) The throughput is not strongly sensitive to frame size
> > 2) 200 bytes is a good 'compromise' selection for frame size
> >
> > Besides, STANAG 5066 has the ability of doing DRC (Data Rate Change)
> > in accordance with SNR values so what is suggested by that white
> > paper, I think, is not applicable.
>
> That's somewhat of an implementation detail that shouldn't affect code that tries to dissect those packets.

While I was writing this I was aware that I was diverging from the
topic a little yet I wanted to add that since now I use DLT_USER0 and
there are header and payload size fields at the Wireshark interface
where I associate DLT_USER0 and s5066mac dissector. So I thought it
may be helpful to provide that information. Sorry if I bothered with
implementation details.

> > Precisely. Yet may be a little clarification is needed. You might have
> > noticed that in my first e-mail I mentioned about DTS (Data Transfer
> > Sublayer) and that one of our dissector methods has the name
> > dissect_s5066dts() but now we are talking about MAC layer and all this
> > may look like a confusion but it is not. As explained in Isode white
> > paper there are three versions of STANAG 5066. MAC (Medium Access
> > Control) layer was introduced in Edition 2 (which was later renamed as
> > Edition 3) and designated to manage HF modem interface that DTS was
> > designated to do the same before.
>
> So is there a publicly-available specification that documents what the packets using this link-layer type look like?-

Unfortunately no, there is not. As in SIS Layer dissector this is also
a part of a standard which is available only to NATO member states and
that therefore we access through an account. However there is a
version called 1.0.2 on the Internet and there you may find the
section C.3 Structure of sublayer protocol data units (D_PDUs) in
order to observe what a DPDU header looks like.  This is a really old
version and I think that's why it's unclassified. Here is the link,

http://www.armymars.net/ArmyMARS/HF-Email/resources/stanag5066.pdf

Besides this I will check if I can provide any recent versions of DPDU headers.

Thanks,

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-- 
M. Baris Demiray
-
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