[Info-vax] What would you miss if DECnet got the chop? Was: "bad select 38" (OpenSSL on VMS)

[Johnny Billquist]

On 2016-10-01 20:47, Dirk Munk wrote:
> David Froble wrote:
>> The way I understand it, DECnet IV doesn't know a thing about IP.  It is
>> a feature in Multinet that does the routing over IP.  So when you
>> mention DECnet over IP as if it is a DECnet feature, you've skirted
>> reality.
>
> I think it is using a kind of IP tunnel, at least it is using IP port
> 700. I will try to find out what it does exactly. Just routing is
> impossible of course, DECnet Phase IV packets are very different from IP
> packets, and can not be handled by an IP router.

First of all, for someone who pretends (or claims) to know so much about 
TCP/IP, you should know that there is no ports in IP. That comment is 
just plain bad.
Second, you really should learn the topic before firing off all the 
silly comments you do.

David is entirely correct. The Multinet DECnet-over-IP really means that 
DECnet is totally unaware of TCP/IP. Yes, the Multinet tunnels can use 
both UDP and TCP, and the default port in both cases are 700.

 From DECnet point of view, it is just a simple line. Called something 
like TCP-0-0. And you work with it just like any other line in DECnet. 
It's a point-to-point line, over which DECnet establish a circuit to the 
remote machine. No different than if you were to just have a simple 
RS-232 cable between two machines, using DDCMP, and then have DECnet 
communicate over that.

Really, this is identical.

Multinet then have a tool to define the TCP/IP connection between the 
two points, which is totally outside the knowledge of DECnet.

And in the Multinet tool, you define the remote host and port. Multinet 
will then establish that connection, using TCP or UDP. And once it is 
up, then from the DECnet point of view, you have a link which transports 
bytes between the two nodes, using that line.

DECnet can route things just as normal. One more line does not change 
anything fundamentally. It's just a line.

The two nodes so connected could be on the same or different areas. All 
that is required is that DECnet can do routing, which have nothing to do 
with TCP/IP.

And the TCP/IP layer just have a connection between the two machines, 
using the normal TCP/IP network. And what is transported on that 
connection is totally irrelevant, as far as TCP/IP is concerned. It's 
just bytes.

Now, how hard can it be to understand?
And in which way is this bad?
And if you have phase V nodes that talk to each other, using whatever 
transports and protocols they want, in which way does that matter here?

And finally, yes, I've implemented this same functionality in RSX, and 
thus RSX and VMS nodes using DECnet phase IV can communicate with each 
other, using the Internet. In fact, I am using this today with HECnet, 
which is a Phase IV DECnet, which covers most of the world, actually. 
And we use these Multinet links all the time (it's not the only 
transport, but it is one, and it works).

	Johnny