[HECnet] Multics online as node 1.770 (BANAI)

[Paul Koning]

> On Sep 7, 2018, at 1:22 PM, Dave Wade <dave.g4ugm at gmail.com> wrote:
> 
>> -----Original Message-----
>> From: owner-hecnet at Update.UU.SE <owner-hecnet at Update.UU.SE> On
>> Behalf Of Paul Koning
>>> On Sep 6, 2018, at 7:47 PM, Jeffrey H. Johnson <jhj at trnsz.com> wrote:
>>> 
>>> ...
>>> Other things being worked and in various stages of completion are X.25
>> networking and IBM 3270 terminal support. If we can complete the X.25
>> support, I envision creating a 'BAN X.25 PSDN', a virtual hobbyist
>> Telenet/Tymnet-like PSN network for X.25 systems. There are other exciting
>> Multics projects in progress by other parties as well.
>> 
>> X.25 is basically a datalink layer (HDLC with some tweaks).  What would
> such a
>> virtual network look like?  I figure something like tunneling X.25
> semantics
>> over TCP, or something along those lines.  Or sending approximate X.25
> PDUs
>> over UDP, the way the SIMH DDCMP implementation does for that data link.
> 
> Isn't X.25 is a network layer. Virtual Circuits span multiple HDLC links.
> Not sure if RFC1086 or RFC11356 are still relevant.

X.25 is a bit of a mess.  Mostly it's a datalink.  If you squint you can think of it as a network layer protocol for endnodes only.  X.25 doesn't appear inside the network; I vaguely remember references to "X.75" for that.  It looks a lot like the data analog of conventional telephone networks: it describes the wire to the exchange, and how you dial phone calls and what phone numbers look like.

	paul