[HECnet] DECnet session control specification

[gerry77 at mail.com]

Hello everyone!

During the last week or so I've spent many hours studying some DECnet
traffic because I was willing to better understand its inner working.

Well, I've discovered that the session control specification commonly
available on the Internet (V1.0) is not the latest, and it seems that
another newer version is not readily available.

While other DECnet protocols such as DRP and NSP appear to be current (and
in facts their description matches actual data captured from the Ethernet),
the SCP is obviously different both in formal definition and in practice.

For example, the specification states that for V1.0 the version field should
be 000 binary, but VMS sets it to 001 and a bit field that should be
reserved for future use and always set to zero has actually a meaning (at
least one bit seems to be used to signal proxy access requests).

So the question is: does anyone here has a copy of a newer session control
specification or at least knows which are the the differences between V1.0
and the following (V1.1?) version?

Thank you very much,
G.