mshiels@tmsoft.uucp (Michael A. Shiels) (03/22/91)
Is it true (and can someone point me to) that the University of British Columbia has implemented an X.25 protocol layer for Unix?
jim@cs.strath.ac.uk (Jim Reid) (03/25/91)
In article <1991Mar22.020730.2018@tmsoft.uucp> mshiels@tmsoft.uucp (Michael A. Shiels) writes:
Is it true (and can someone point me to) that the University of
British Columbia has implemented an X.25 protocol layer for Unix?
Yes. UBC implemented X.25 for BSD, giving 4.[23] BSD X.25 sockets. It
was available to academic institutions for a nominal sum - something
like $100 Canadian. The code was part of UBC's efforts on the EAN
X.400 messaging system. It used the synchronous port of DEC's DMF32
board to drive the X.25 line. I understand that the whole project was
being moved on to Suns. We were happy users of this code for a few
years, but since the X.25 line were moved, I haven't been following
what UBC were doing.
Here's some old mail from UBC about this code. [Notice the date.]
Things could have changed a lot since then.
Received: from cs.ucl.ac.uk by Robin.Cs.Nott.AC.UK id a009127; 9 Jun 86 7:31 BST
Received: from EAN.VAX2.CS.UCL.AC.UK by vax2.Cs.Ucl.AC.UK via EAN id a000503;
9 Jun 86 7:25 BST
Date: 8 Jun 86 19:32 PDT
From: John Demco <demco@ean.ubc.cdn>
^^^^^^^^^^^^^^^^^
Should this be demco@cdn.ubc.ean??? - JR
Message-ID: <3038:demco@ean.ubc.cdn>
Subject: UBC X.25 kernel software
Hi, my apologies for keeping you waiting so long for a response from
UBC. Below is a short description of the 4.2BSD X.25 software available
from UBC. If you are still interested in the software, please let me
know and I will send you the license forms. (The cost is a distribution
fee of $Canadian 100.) The X.25 implementation will also be included in
future versions of EAN for BSD UNIX.
Regards,
John Demco
===========================
UBC X.25 software for 4.2 BSD
This document briefly describes the X.25 software package
available from the University of British Columbia (UBC). This
software package is available to Academic users on completion of
a license agreement. The software has been developed over the
past few years by various individuals both in the Computer
Science Department and the Computing Centre. The software runs
both in 4.2 BSD VAX systems and some SUN workstations. However
due to licensing restrictions this software distribution only
contains VAX support.
The software comes in two flavours: the 'classic' X.25
point-to-point version and the X.25-over-Ethernet version. Both
versions can be run simultaneously.
This document assumes a working familiarity with the ISO
Open Systems Interconnection (OSI) model. The description is
modelled along OSI lines.
CLASSIC X.25 SOFTWARE
This software allows the UNIX system to function as a X.25 DTE.
It can be connected to either a private (e.g. UBCnet) or public
(e.g. DATAPAC or TELENET) X.25 network over a standard
synchronous link. The software allows the host to make outbound
X.25 network calls to other X.25 hosts and to receive inbound
X.25 calls. The various pieces of software reside at the
physical, link, packet and application layer.
o Physical level software
The software currently supports two synchronous hardware devices.
* DEC DUP device. This is a single character non-DMA device. It
has been around for a long time and allows systems to be X.25
connected for a modest cost.
* DEC DMF device. This is a DMA synchronous device that has
less host overhead but is more expensive.
o Link level software
There are two pieces of software that provide the HDLC elements
of procedure in DTE LAPB mode.
o Packet level software
This layer of software provides the network level of X.25. It
currently supports the 1976 and 1980 levels.
o Application layer software
This term refers to the pieces of software that make the X.25
layers useful. The 'pseudo-tty' driver is changed. In addition
there are changes to the login process. Incoming calls are
handled using the X.29 daemon and outbound calls are handled
using the NIM daemon. In addition there is an x25config program
that allows you to tailor the configuration of your X.25
environment dynamically.
X.25 OVER ETHERNET SUPPORT(XE)
This software implements the necessary procedures to allow you to
run X.25 between components that are on an ethernet. This
implementation predates the International recommendations and is
a direct port of the UBCnet implementation. UBCnet is the local
area network developed and run by the Computing Centre at UBC.
This software resides as a link layer entity in the hosts
and as such builds on all the existing upper level software. The
UBCnet implementation uses the IEEE 802.2 Class I and II elements
of procedure for maintaining connections to other
ethernet-attached components. The software includes the following
components:
* A modified 3COM ethernet driver that allows the same hardware
device to be used by both the TCP/IP and XE families. We have
experienced no problems in using the ethernet with different
protocol families.
* The link layer entity that masquerades as a link layer yet
provides the XE functionality. This layer uses a
proceduralized interface to the IEEE 802.2 elements of
procedure.
As mentioned previously, the upper layers are unchanged and
are common to both the 'classical' and XE implementations. More
details on the XE implementation are available on request.
PLANNED EXTENSIONS AND ENHANCEMENTS
We intend at some point to incorporate X.29 support into the
kernel. This is primarily for efficiency reasons. The current
framework is quite workable but this extension would give the
whole package more of a 'production' feel. In addition we might
construct a network call program that would make outbound calls.
===========================
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rayan@cs.toronto.edu (Rayan Zachariassen) (03/28/91)
Last I heard, the UBC X.25 has been donated to UCB for possible inclusion in a future BSD. FYI. sigh...