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

[David Froble]

Michael Moroney wrote:
> Johnny Billquist <bqt at softjar.se> writes:
> 
>> 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.
> 
> Oh, that is interesting. So the Multinet DECnet over IP is just a
> virtual point-to-point serial line, not a fake Ethernet like I was
> thinking it might be.  Real point-to-point links were common in the
> early days of DECnet before ethernet pretty much took over for
> short distance links.
> 
>> Multinet then have a tool to define the TCP/IP connection between the 
>> two points, which is totally outside the knowledge of DECnet.
> 
> So for a more complicated network, you'd need several of these virtual
> point-to-point links so everyone could talk to everyone else.

Well, what I understand, which is little, all you need is one connection between 
two networks, or, one connection for each remote network.  But, I know little.

> I don't know offhand if DECnet V has support for point-to-point links
> at all but if it does, Multinet's virtual p-p links should work with
> it as well. But with OSI over IP, there is no need other than to talk
> to a Phase IV node.
> 
>> 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.
> 
> That makes sense.  A TCP link from A to B with a driver for a virtual
> serial line on each end that puts the stuff over the TCP link.
> (Or UDP. I don't know the advantage of one over the other for something
> like that)
> 
>> DECnet can route things just as normal. One more line does not change 
>> anything fundamentally. It's just a line.
> 
> 
> 
> As to the argument over the Multinet Phase IV p-p connections and the
> Phase V OSI over IP stuff, there is no reason why both can't coexist,
> as long as they use different TCP/UDP ports. To IP it's just more
> TCP/UDP packets.

Two totally different and separate connection types.

> As to VSI, for Phase IV it's just a matter of not breaking anything
> in the Multinet code.

As I understand it, correct.

> For Phase V it may depend on working on the
> Multinet PWIP driver, or maybe it will just work.

Again, I do not know details, but, it sure sounds like the implementation was 
within DECnet, and it just uses TCP/IP, and any TCP/IP should work.

It will be of interest to me, out of curosity, to see if indeed any additional 
work is required, or if Phase V will "just work".