🚀 go-pugleaf

In article <ej.713727684@cc.univie.ac.at>, ej@cc.univie.ac.at (Ewald Jenisch) writes:
|> ssw@bronze.ucs.indiana.edu (steven wallace) writes:
|> 
|> >We're considering using STUN to connect a local 3725 to a remote
|> >3725.  Anyone have experience using STUN to connect IBM FEPs?
|> 
|> Yes, we've done exactly that -- at least with partial success. Our
|> only problem was that the SNA-tunnel can't get through frames larger
|> than about 1500 or 2000 bytes unfragmented.
|> 
|> If I remember right, this isn't actually a problem with the tunnel
|> itself, but rather a limit of the hardware of the serials: they are
|> limited to 1500 or 2000 bytes (don't remember the exact figure
|> though).
|> 
|> If fragmentation isn't a problem for your SNA-applications you should
|> be happy with the STUN connecting FEPs though. We've had no
|> configuration tuning besides proxy-poll in order to keep the WAN
|> responsive.
|> 
|> On the software-side we used 8.3(1) and 8.3(3). (we've done our tests
|> some months ago)
|> 
|> -ewald
|> 
|> --
|> Ewald Jenisch                      |  E-mail: ewald.jenisch@cc.univie.ac.at 
|> Vienna University Computer Center  |          z00ejr01@awiuni11.bitnet
|> Universitaetsstrasse 7             |  Tel: +43 (222) 43-61-11 x251  Fax x170
|> A-1010 Vienna, Austria             |  NIC-Handle: EJ63
|> 
|> 
|> 
|> 

We ( SAS Institute Inc ) tried STUN between FEPs and ran into the same
problem.  In particular, when we ran SAS ( our favorite program ), it
failed.  Other applications like SPF ran OK.

To improve performance, SAS apparently draws its screens with large writes.
4k or so it seems.   I haven't talked to the developers, this is from
analyzing the data stream.

We looked into adjusting some parameters on the FEPs to limit the max
data size but it was thought performance would suffer too much.

Due to various other considerations, and lack of a pair of FEPs to test
with, we punted and just multiplexed the circuit.  Sigh.


So, how did you get around the 2k limit?  Tweek some VTAM parameters?



David Cherveny				djc@unx.sas.com
Systems Programmer, networking
Network Support Dept
SAS Institute Inc.

( SAS is a registered trademark of SAS Institute Inc. )