11 Apr
2023
11 Apr
'23
4:42 p.m.
On Apr 11, 2023, at 10:31 AM, Johnny Billquist
<bqt(a)softjar.se> wrote:
On 2023-04-11 14:38, Paul Koning wrote:
I always thought of circuit names as more or less a
suggestion, and certainly seeing circuit names in Phase II reinforced that. The specs
have them as ASCII strings, no constraints (though TOPS-20 Phase II is severely
constrained by implementation choice). So the way to deal with circuit names is just
that, as ASCII strings subject to the length limit in the spec but not otherwise
constrained.
In at least RSX, they are not just random, format free strings.
They are in the form dev-#, dev-#-# or dev-#-#.#. All which signify things, and parts can
be wildcarded.
Indeed, for any given implementation there are patterns and they are followed
semi-consistently across implementations. But the architecture spec has no rules other
than that circuit and line names are "id-string". The only place I see the
dev-# type format mentioned isn't for the names but rather for the value of line
attribute "device".
Also, even when an implementation follows the RSX pattern, the actual names used may vary.
For example, async DDCMP on RSTS uses circuit names of the form TT-# no matter what
controller type is involved.
It gets worse when you consider Phase II, where circuit names contain underscores rather
than hyphens. So for an application that reads circuit and node info from other
implementations, the rule I would suggest is to assume nothing about the structure of
circuit names.
paul
On Apr
10, 2023, at 9:09 PM, Johnny Billquist <bqt(a)softjar.se> wrote:
On 2023-04-11 03:04, Thomas DeBellis wrote:
PyDECnet is trying to follow the DECnet
architecture specs closely (even to the point of being struturally similar, something
other implementations tend not to do).
Yes, I was catching up on that, but perhaps not
keeping up with it...
:-)
Seems unlikely that any code in netpth would be based on the behavior of PyDECnet, but
anyway, that detail will improve soon. So
what's the bottom line here? Is netpth rolling over and dying actually legitimate or
is there a better algorithm to use?
I don't think there any better algorithm. Why netpth throws errors is also unclear.
Maybe it has a more rigid idea on how circuit names should look? PyDECnet allows pretty
much anything as a circuit name. DEC was a bit more conservative... I think you need to
dig around on that maybe.