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:
FYA, I figured it out, reading the listings I found. It's pretty simple. I now have
PyDECnet serving up that data, and TOPS-20 seems to like it:
17:52:40 -- Network topology --
Nodes on-line:
PYTS41
NCP>
17:56:18 -- Network topology --
Nodes on-line:
28NH MIM PYTHON VENTI2
The first message reports the router (as a result of bringing up the KDP link); the second
report shows the additional nodes reported by the TOPOL server. For the moment, I have it
report (a) nodes known to be reachable from here by the routing tables, and (b) any nodes
explicitly listed in a list of names given to the program. MIM and VENTI2 are there
because of (b).
Now I need to fix my intercept code. It doesn't currently convert Phase II to IV
headers correctly, but that's not hard. The harder part is tracking connection state,
which is needed only if TOPS-20 ever sends packets for an active connection without route
headers. Intercept allows that -- it only requires route headers on some packets, like
Connect Initiate obviously. For that to work, the intercept has to keep track of open
connections and their source/dest, so it can supply the correct addresses if it gets a
packet with no route header.
paul