Re: ATM/Token Ring Network (TCP/IP)

Hello Dwayne,

exactly my point of view !
I  ALWAYS had a struggle with network providers when loosing
connections on 5250 sessions, they ALWAYS tell you its your
sort fo "timeout" settings that must be wrong and it ALWAYS
came out that there either was a bad config in their routers OR
a faulty line.
A little story on this (I have others of this sort):
We were migrating a private network in germany with seven
locations connected to a main site through frame relay from one
provider to another and using a different carrier.
Some locations went smooth, but in Hamburg for example, it
was a mess ! Since 13th of december 2001 (!) we told them, we
are having problems when sessions drop during working hours
(main site in different location, one central AS/400).
Until last week (!) they sent technicians from the carrier, the
network provider sent his people, they made me change settings
on the AS/400, we checked everything on our side ...
They "improved" their router configs nearly every day ..
Finally it was a "synchronisation" problem on the (physical) line
as they told us, they exchanged the modem on that site and
made a change in configs to put in "filler frames" to keep up
synchronised.

Since then we are up and running with no further problems
at all !

The problem with this error was, that nobody ever saw a
definitive error logged anywhere, so everybody involved
said "with our equipment everything is 100% okay" but still
we were loosing contact several times a day.
They found out using a lanalyzer for several days, then.

I know that ATM sometimes has similar problems, but I'm
not very familiar with it, maybe it's worth a shot.

HTH, Philipp Rusch

Dwayne Lindner schrieb:

> >
> > This is a multipart message in MIME format.
> > --
> > [ Picked text/plain from multipart/alternative ]
> > AS/400 620 with a 2816 ATM network card going to an IBM 8274
> > hub, going from one IBM 8270 to a remote IBM8270. It's the
> > PC's on the remote 8270 which are freezing. No major network
> > traffic, and none AS/400 traffic is carrying on as normal,
> > it's just the 5250 sessions which are freezing. A WRKACTJOB
> > shows them as status RUN but taking no CPU cycles.
> >
>
> Using TCP/IP I take it ??
>
> Get your network boffins to check, double check, and triple check the router
> configs.
>
> I've had a few similar situations and in every instance it's been a stuffed
> router or other network config.
>
> You can fool around with your tcp configuration and stuff, but I doubt it's
> the problem unless your timeout values have been changed from the defaults.
>
> Dwayne Lindner
> Team Leader - Data Centre
> Wesfarmers Rural Information Technology
> 184 Railway Parade, Bassendean WA 6054
> Ph: (08) 9273 5365    Mob: 0407 386 693
> Email: dwayne.lindner@writ.wesfarmers.com.au
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