On real MicroVAX running OpenVMS with networking, hook up the [ELIZA]
feedback psychiatrist program to a VAX Phone automatic responder, kind
of like a chat bot.
So, someone on the network could do PHONE MARIAH::[ELIZA] and it will
be answered by [ELIZA] and a dialog would ensue.
The DEC PHONE protocol is not a complex protocol, and you'll either be
reversing that protocol, or scrounging up a copy of the PHONE source
listings and skimming through that. The PHONE protocol hasn't changed
For the meddler-in-the-middle approach to reversing the PHONE protocol
here, present a spoofed object 29 on one DECnet host and connect to
PHONE object 29 on a second, connect a PHONE client to the MITM host,
and then read and log and pass messages between between the client and
the (real) server.
There was a PHONE "tee" program written in DCL back some 25 years ago
which initiated calls to two different users, connecting those two
users together, having spoofed to each the other user as the caller.
There were other similar programs that sent mail directly using the
MAIL-11 protocol. Not that I have samples of either genre immediately
As these spoofing tools became more prevalent, DECnet was "hardened" to
(optionally) require privileges for certain connections. Not that
requiring privileges did or could do much with any compromised hosts.
Some 🤡 discussed that security detail here:
In addition to the above, here are some DECnet task-to-task and
to-object DCL examples, some of which target PHONE-11.
And for those unfamiliar with ELIZA:
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