17 Jul
2025
17 Jul
'25
4:45 p.m.
On 2025-07-17 16:05, Paul Koning wrote:
First of all - no. I don't have any specs. But yes, there are RFCs that
do mention carrying DECnet over IP. I don't remember any details now,
but I think they might not even actually be using TCP in those, but my
memory is very hazy. But I do have a gut feeling that it's not the same
thing that Multinet does. Remember, not only are we talking about how
the encapsulation is done, but then the fact that we're really trying to
look like DDCMP in there, so we have the specifics of DECnet over a
DDCMP link, which is all the different types of packets for init, and
negotiations, and so on.
While it of course is possible that DEC did that, it would seem that it
would make more sense to do something more "clever". And OSI
specifications did also touch upon this encapsulation over IP which is
more OSI generic. And DECnet phase V is that, so it seems more likely
that they went down that crazy route.
Ethernet is so simple in comparison. :-)
And there, interoperability between phase IV and phase V is pretty
straight forward, tested and supported.
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt(a)softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
On Jul 17, 2025, at 9:39 AM, Paul Koning
<paulkoning(a)comcast.net> wrote:
I found it in the VMS manuals, and they point to some RFCs. I'll read those. On Jul 16, 2025, at 6:42 PM, Johnny Billquist
<bqt(a)softjar.se> wrote:
On 2025-07-16 14:29, Paul Koning wrote:
Oh. I hadn't thought about two independent solutions to DECnet over TCP. Is the DEC
answer indeed different? If so, do you know where to find specs for it? > On Jul 16, 2025, at 6:22 AM, Trevor Warwick
<twarwick(a)gmail.com> wrote:
>
> Decnet+ aka Phase V will talk to HECnet perfectly fine.
I set up my DECnet/VMS Phase V node (x86) to talk to PyDECnet, over Ethernet. Works
fine. I have not tried it over Multinet/TCP but I wouldbesurprised if that fails,
there's nothing in the Multinet "protocol" thatis Phase V dependent,
obviously, and VMS is usually pretty good about clean layering.
Paul, any reason why you think DEC would have done the same thing Multinet did, which is
DDCMP inside TCP with 4 byte headers, two being length, and two just ignored?
As we've discussed plenty of times in the past, the Multinet solutionis really a bad
back and abuse. And I've never heard anyone reporting tohave connected a Phase V
node's DECnet-over-IP to a Multinet Phase IV node DECnet-over-IP.
It's not about the compatibility between the implementations of DECnet in the phases,
but about how you encapsulate the whole thing if you want to use TCP as the carrier...