[HECnet] DECnet/Python

[Paul Koning]

> On Oct 27, 2021, at 9:32 PM, Thomas DeBellis <tommytimesharing at gmail.com> wrote:
> 
> TOPOL?  Hmm...  No, I hadn't heard of that, either.  It sounds almost familiar, but I don't know why Tops-20 would be asking for it because it  doesn't appear to be serving it, viz:...

I'm guessing it has to do with learning the shape of the Phase II network.  That's an entirely different problem than Phase III and later.  The connect is by name, so object 0, object name TOPOL.  And I don't have anything to answer that request so I have no trace.  I suppose I could build a dummy responder just to see what question is asked.

If indeed it's Phase II topology related, it would make sense for the host not to have that server, and of course it would also go away in Phase III.  The host requests, but does not offer, "intercept" which is node name based routing in Phase II that was implemented only in a few places.  Somewhere I saw that it exists only to get past the front end (on larger machines) which was handled as a separate node so it counts as a network hop.  Without intercept, Phase II only goes a single hop.

I implemented a primitive skeleton version of intercept in PyDECnet, so the 2020 system sees me offer the service; that may be why it asks for TOPOL.  

	paul