RE: How to Utilize Parallel SNA Connection

["Pytel, Alexei" <pytela1@xxxxxxxxxxxxxxxx>]

You will have to read about APPN class-of-service.
When session is started, you speciy the mode (MODD) you are going to
use. The mode in its turn points to class-of-service (COSD).
Class-of-service is a table, used to choose a path (link) used for a
session if there's more than one. COSD uses several criteria for
choosing a link, like link speed, propagation delay etc etc. All these
are taken from CTLD, which represents the link.
You may try to play with these parameters in CTLD (they do not
influence, how link works - only how they are chosen, so you are safe to
set any crazy values).
Unfortunately, standard COSDs are not awfully selective, so it may not
work.
Then you may try to create a COSD of your own with distinctive
preference for SDLC link and associate your MODD with it. It's actually
easy to do, but not very obvious from the first glance. So brace
yourself for some trial and error.
Another ways to achieve what you want could be to configure a separate
local/remote APPN LU pair (remote location/local location) to be used by
APPC device on SDLC link.
It may also fail, because APPN can discover it can reach same LU with a
"better" link (in terms of COSD) and you will end up on LAN link again.
APPN search can be suppressed by rejecting CP-to-CP sessions on ALL
CTLDs for the same partner, or declaring partner as a *LENNODE.
But this may also be defeated by APPN if you have a network node which
knows all locations.
(Normally this will work, but I cannot tell for sure without knowing
exact topology of your network).

You can suppress APPN and use plain APPC support (APPN(*NO)). This will
require more manual configuration and separate LU/LU pair is a must.

My recommendation is to spend time on understanding APPN
class-of-service support. It's easier than it looks.

    Best regards,

          Alexei Pytel



> -----Original Message-----
> From: Larry D. Bolhuis [SMTP:lbolhui@ibm.net]
> Sent: Thursday, December 10, 1998 2:29 PM
> To:   MIDRANGE-L@midrange.com
> Subject:      Re: How to Utilize Parallel SNA Connection
> 
> OK,
>   So now I have created a new MODD and assigned it ONLY to the new
> link. When I start passthru the
> new mode automatically assigned itself to the LAN link and I STILL go
> via the LAN!  The device
> description on the LAN link is setup for *NETATR for the mode.  How do
> I stop that device from
> automatically allocating and using the new mode?
> 
>  TIA - Larry
> -- 
> Larry Bolhuis         |
> Arbor Solutions, Inc  | Two rules to success in life:
> (616) 451-2500        | 1. Never tell people everything you know.
> lbolhui@ibm.net       |
> 
> Eric DeLong wrote:
> > 
> >      Have you defined a Mode Description that's unique to the new
> link?
> > 
> > ______________________________ Reply Separator
> _________________________________
> > Subject: How to Utilize Parallel SNA Connection
> > Author:  <MIDRANGE-L@midrange.com > at INET_WACO
> > Date:    12/7/98 1:43 PM
> > 
> > How can I cause Passthru, DDM, etc to utilize a second SNA
> connection between
> > two AS/400's?
> > 
> > The setup is a LAN connection (via Routers) and an SDLC connection
> (Leased
> > line).  All the traffic
> > goes across the LAN but it is desired that non-interactive traffic
> travel the
> > SDLC link.  The leased
> > lines/controllers/devices are up (using a second APPN Transmission
> Group
> > number).  No matter what I
> > try all APPC traffic falls back to the LAN.
> >
> +---
> | This is the Midrange System Mailing List!
> | To submit a new message, send your mail to MIDRANGE-L@midrange.com.
> | To subscribe to this list send email to MIDRANGE-L-SUB@midrange.com.
> | To unsubscribe from this list send email to
> MIDRANGE-L-UNSUB@midrange.com.
> | Questions should be directed to the list owner/operator:
> david@midrange.com
> +---
+---
| This is the Midrange System Mailing List!
| To submit a new message, send your mail to MIDRANGE-L@midrange.com.
| To subscribe to this list send email to MIDRANGE-L-SUB@midrange.com.
| To unsubscribe from this list send email to MIDRANGE-L-UNSUB@midrange.com.
| Questions should be directed to the list owner/operator: david@midrange.com
+---