[Info-vax] Rethinking DECNET ?

[Johnny Billquist]

On 2014-09-04 10:32, Jan-Erik Soderholm wrote:
> Johnny Billquist wrote 2014-09-04 00:53:
>> On 2014-09-03 16:53, Dirk Munk wrote:
>>> No, it is not a tunnel. There is no principle difference between Decnet
>>> over OSI and Decnet over IP. The transport layer is different, that's
>>> all.
>>
>> DECnet over OSI? What does that mean? You say it like you are implying
>> that
>> OSI is a separate network protocol from DECnet. DECnet phase V *is*
>> following the OSI model, not running atop of it.
>>
>> With DECnet over IP, the transport layer is actually a whole full other
>> network stack, of which DECnet is totally unaware of.
>>
>>      Johnny
>>
>
> As I understand, and I think we have to separate protocols from
> network architectures here, one can summerize it something like:
>
> DECnet IV is communication based on "DIGITAL Network Architecture" (DNA).
> DNA is a 8 level architecture different from both OSI and the
> architecture used by IP.

I don't know how many layers DECnet phase IV have, but yes. I believe it 
is correct to say that DNA is different than TC/IP or OSI. :-)

> DECnet V  is communication based on "Open Systems Interconnection" (OSI).
> DECnet V was also called "DECnet/OSI" to emphasize its OSI architecture.

Right.

> DECnet V+ (or DECnet-Plus) added support for IETF RFC 1006 ("OSI over IP").
> http://tools.ietf.org/html/rfc1006

I would guess/assume that the additions in DECnet-V+ would be the 
integration with TCP/IP, and a TP0 driver for the DECnet stack which 
then tunneled the traffic over TCP. I can't see that anything else would 
have been needed to change on the DECnet side.

> And since "DECnet over IP" is based on the specification for "OSI over IP",
> I'd guess that you can't easily shoehorn that into DECnet IV. Either you
> would change DECnet IV to use the ISO model (but then you have DECnet V),
> or you develope a whole other interface to IP not based on "OSI over IP".

Tunneling DECnet phase IV over IP have been done for more than 20 years. 
But you are right in that they do not follow RFC 1008, since this is not 
using TP0.

I don't even believe Multinets tunneling is compatible with Ciscos. So 
no standards means you are a bit more limited...

> And if you still *need* DECnet (I have not used it for anything on my
> production systems the last decade, they are IP-only), you might
> better learn and used DECnet V+.

That I disagree with. DECnet over IP exists for phase IV as well, have 
done so for a very long time.

	Johnny