[Info-vax] Rethinking DECNET ?

[Jan-Erik Soderholm]

Johnny Billquist wrote 2014-09-04 13:25:
> 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
>

My point and question was actualy, "do you realy need DECnet?" :-)

I have no problem running VMS without DECnet and the
customer will never ask for it, that is for sure...

Jan-Erik.