Microsoft Host Integration Server 2003 lacks APPN
Virtual Node (aka Connection Network) functionality.
When LPAR1 is the Primary Network Node Server for HIS.
ALL sessions orginating or terminating in the HIS Server
will pass through Intermediate Routing Node LPAR1.
This solution will cause a lot of unnecessary Mainframe I/O
and usage cpu cycles. This APPN Network consist of some 30
APPN nodes as well as some 25000 sessions in prime time.
+------+ +-------+ +-------+
| | | | | |
| HIS | | LPAR1 | | LPAR2 |
| EN | <- EE -> | NN | <- EE -> | NN |
| DLUR | | DLUS | | |
| | | CDS | | |
+------+ +-------+ +-------+
To eliminate this perceived problem we propose to use the
SNASw Virtual Node capability. If this works no sessions
will run through LPAR1 between the HIS and LPAR2.
<------ Downlink ------> <------ Uplink ------>
VN
+------+ +--------------+ +-------+
| | | | | |
| HIS | | SNASw | | LPAR1 |
| EN | <- EE -> |.......+......| <- EE -> | NN |
| DLUR | | BrNN | EN | | DLUS |
| | | | DLUR | <- | CDS |
+------+ +--------------+ \ +-------+
\
EE +-------+
\ | |
\ | LPAR2 |
-> | NN |
| |
| |
+-------+
The above scheme results in the following
- All PU and LU of the HIS Server are registered with the
SNASw directory database.
- A APING from the Mainframe LPAR1/2 to the HIS Control
Point name will show a route containing the SNASw & HIS
nodes. Sometimes however the route will end with the SNASw.
- Session requests for 3270 LU (DLUR) always seem to arrive
at the destination LPAR, but the reversed path runs into
trouble with sense codes like 08060031, 08900037
AIW document :
APPN Branch Extender Archtecture Reference
6.8 Local Independent LUs and DLUR Support on BrNN
explicity states :
Support for DLUR is optional on a BrN, but DLUR is so
important that we can't imagine any Branch Extender product
leaving it out
The footnote on the same page states :
Without option sets 1116, 1122 and 1123, a DLUR downstream of
BrNN would be broken because the BrNN represents itself as the
ENCP owning all domain resources; therefore searches involving
a downlink DLUR with the Owning-CP-Respond indicator set would
not work right.
So does anyone know for sure that this is fully supported in the
SNASw or is it not allowed. SNASw Design and Implementation Guide
states : SNASw does not support DLUR routers cascaded downstream
from another DLUR.
The IBM DLUR/DLUS architecture (supported by SNASw) has a
restriction that if a DLUR is required, it can only be implemented
in the DLUR directly connected to the upstream DLUS NN server host.
THe above architecture reference is in conflicht with the AIW
document content. Please clarify.
