🚀 go-pugleaf

> From: Peter Elford <munnari!csc.anu.oz.au!pte900@uunet.UU.NET>
> Subject:      SUNLINK Users ??
>
> Has anyone got some experience with the SUNlink product that makes a SUN
> 3/160 look like a local controller to an IBM/MVS host and hence provides a
> TCP/IP gateway to the IBM host for other TCP/IP machines on the same netwrok
> as the SUN ?

I have some experiencing with the SunLink SNA-3270 product. This one emulates
a 3274 controller with a synch SNA connection. There is another one that
connects directly to the channel - it's called SunLink Local-3270, but I
have never used it.

>
> I would be interested in:
>     1) functionality - terminal emulation, file transfer ??

The software consists of a "3274" server - a UNIX daemon which controlls
the lines, and accepts up to 32 DataSream-3270 peers. These peers are
implemented with RPC/XDR. To each of these peers (LUs) one can connect a
terminal emulation program (te3278) that works on the Sun console on any
other termcap(5) supported terminal, with user-definable keys etc. There
is also a local printer emulation (pe3278) which impelemnts the screen
prints and send it to the Unix printer spool.

File transfer is accoumplished via the same 3270 stream the same way
PCs do it with various 3270 emulators. The te3270 has the hooks necesary
to start a file transfer from an emulation screen, and on the IBM you
need an additional peice of software provided by IBM. (SunLink
installation guide mentiones the part numbers). You may already have
those if you use PCs with file transfer via 3270.

As to the "relay" feature of it, there are two things to mention:
1. a te3278 terminal emulation process that runs on ANY Sun on the
network can connect to ANY sna3274 daemon, thus sharing the LUs is
trivial. Moreover, the various 3274's are published via YP.
2. Any terminal that connects to a Sun (WorkStation or Server) via a
TELNET or Rlogin, can use the terminal emulatorbut with file transfer is
not that easy.

>     2) speed

The pefrormance of this software has the "feels" of any other 3270
emulation on an ascii terminal. The software overhead on the Sun CPU
using a 9600 synch connection is neglectable. Therefore I presume that
the Local-3270 product can acheive real good speed. (It needs a
pecialized hardware for the channel connection though...)

>     3) cost effectiveness as compared to other IBM<->TCP/IP options ?

As costs are concerned, the SunLink solution is real cheap. For one SNA
connection you can get a SUN-3/60S (3 Mip server) for ~7,500$ and the
rest is only software 1k$-2k$ approx. But you cannot and must not
compare this to a full TCP/IP membership on an IBM, see below.

>     4) pros and cons

The SunLink solution (among others, e.g. Bridge w/ SNA) is worth ONLY
for logging in Sun and other TTY users to an IBM, it is not a full
networking solution for you IBM system. For a typical commercial
organization this might be good enougth, but when you need E-Mail and
direct FTP access to IBM discs from any machine on the network, I'd much
prefer to have full TCP/IP on an IBM, for all it costs.

If I compare the SunLink solution to ther 3270 emulators for asynch
terminals, and there are quite many of those in the market, the SunLink
is most appropriate if you already have SUNs and need mainly the
terminal emulation function, and cheaply.

>
> Peter Elford,
> Computer Services Centre
> Australian National University,
> Canberra, AUSTRALIA.
>
> pte900@fac3.anu.oz
>

Leonid Rosenboim, CS & Math, Tel-Aviv University, Israel.
[ The opinions are all my own, and I am not working for Sun or any of
their representatives. ]