[comp.realtime] Excelan EXOS TCP/IP Software Problems

sardella@strfleet.gsfc.nasa.gov (Tom Sardella) (04/14/91)

I am working with a custom embedded front-end system that I developed in 1986
which provides a bridge between some special purpose NASA data communication
circuits and a VAX computer.  Ethernet TCP/IP is used as the interface between
the front-end and the VAX.  The TCP/IP implementation on the front-end consists
of Excelan 201 intelligent Multibus controllers running the EXOS 8010 TCP/IP 
version 3.2 code.  This code runs on the EXOS 201 board.  We used the host
development package, which provides Unix host driver source code, to develop
a driver on the front-end host processor (Heurikon HK68ME 68000 board) running
under the VRTX real-time kernel to simultaneously operate 2 controllers.

TCP communications with the VAX have worked flawlessly with this configuration.
However, we have adapted this front-end for use with a MASSCOMP 6600 and have
had problems with the 8010 TCP/IP crashing when the MASSCOMP closes and then
reopens the window.  I was able to fix the problem by copying the version 3.3
TCP code from their PC-based product, an EXOS 205 board (it appears that
exactly the same code runs on all their boards), to the Multibus EXOS 201
board.  Further investigation found that buffer management problems with
version 3.2 were causing an EXOS PANIC and that version 3.3 fixed those
problems.

With that as background, this is my real problem:  I would like to avoid 
problems in the future caused by running old buggy versions of this TCP/IP
software.  I would like to get hold of the latest available version along
with the source code and other documentation (Application Notes on the Bus 
and Message-Level Interface) that are needed for developing and maintaining
the host device driver.  I'd also like to have the proper license to use it.
However, with Excelan having been acquired by Novell, I have had a difficult
time finding anyone that supports this code in any manner.  A couple of
years ago we couldn't even get a straight answer from Excelan on whether
we could purchase licenses to make additional copies of the software.
From what I've seen of Novell's product line, this on-board TCP/IP code
doesn't seem to be used at all anymore.

Even if we can't find current support for this product, I'd like to get the 
latest released version along with the documentation I mentioned.  Switching
to a different product would be a very expensive proposition at this point
and there aren't many vendors that support dual controllers.

Does anyone have any suggestions?  Please email as our news server seems to
have been having problems recently.  I'll post a summary if there is 
sufficient interest.  Thanks in advance.


			Tom Sardella
			Network Control Systems Branch, Code 532
			NASA/Goddard Space Flight Center
			Greenbelt, MD
			sardella@strfleet.gsfc.nasa.gov