[3617] in linux-net channel archive
Re: sna and bridging
daemon@ATHENA.MIT.EDU (Paul P. Norton)
Wed Jul 10 12:52:06 1996
Date: Tue, 9 Jul 1996 12:46:07 -0700
From: "Paul P. Norton" <pnorton@grumpy.biomed.com>
To: mea@mea.cc.utu.fi
CC: linux-net@vger.rutgers.edu
In-reply-to: <96Jul9.111856+0200eet_dst.63435-226+58@mea.utu.fi> (message from
Matti E Aarnio on Tue, 9 Jul 1996 11:18:43 +0300 (EET DST))
Reply-to: pnorton@cts.com
>
>David C Niemi speaks about SNA and Linux
>...
>
>> I have not heard much action on SNA in the Linux community, probably
>> because there is major culture shock between blue-suited big-iron fans and
>> mellowed-out sandal-and-tshirt-wearing Linuxers. It would probably not be
>> all that difficult technically, though, if you want to take it on ;^)
>
> Matti E Aarnio replies...
>
> Actually it is technically difficult. I have heard several
> accounts that SNA is not specified fully at its documentation,
> and that each new VTAM release that IBM puts out has its own
> "features" ( that is, deviations from the specs -- call them
> bugs, if you like ) which must be catered for, and only way
> to learn about them is by using protocol analyzers, and to test...
>
Getting Linux to support all of SNA would be a _major_ undertaking.
Getting Linux to support a subset of SNA (LU 2.0, NJE, etc.) would
not be as bad, but you would still need to implement the lower layer
protocols to support that as well. Token ring would have to be much
better supported in Linux than it currently is. (Speaking of which,
who actually is supporting token ring in Linux, anyway?) SDLC isn't
supported by Linux at all. Forget bisynch. Bisynch isn't even
defined in SNA.
Whether or not SNA is fully documented, the documentation itself is
formidable. I'm looking at several manuals, each about a thousand
pages. They easily fill a shelf.
It's true that each new release of VTAM has new "features", but I
would argue that these new features needn't always be catered to. I have
a few 3174 terminal controllers running microcode that is at least five
years old and they still work fine with recent levels of VTAM. If
companies had to upgrade NCP, 3174 microcode, and the versions of
software of all SNA-connection products every time they wanted to
upgrade VTAM then VTAM probably wouldn't ever get upgraded.
--
Paul P. Norton
pnorton@cts.com
