Access to Multiple EntireX Brokers

Existing VSE with NATURAL 8.2 accessing MF Broker (7.2) via CST SPECTRUM.
Want to add new WEB service to do TAXCALCs.
Installed BROKER (10.3) on Windows and initiated XMLSERVER there.
Cannot communicate to Windows Broker.
Defining to SYSRPC either get 02150148 (can’t find host) or NAT0954 when use Port.
Suspect it has to do with Broker Stubs.
Existing environment on MF uses NATETB23;
New Broker is supposed to use BKIMC;
Is anyone calling different brokers from same NATURAL?
Are they same versions?
Any help appreciated.

I am now thinking that what we need to do is install and run Relay Manager so that we can do TCP communication.

EntireX version 7.2 is out of support.
I strongly recommend to install a supported EntireX version on z/VSE (EXX 9.6).
BKIMC of EXX 9.6 supports TCP/IP out of the box.

Understood and this is the direction. Unfortunately an immediate upgrade causes problems with existing Spectrum Application. So the VB apps need to be rewritten to “.net” before they can be upgraded, so the idea was to install new Broker and gradually migrate the apps as they are rewritten. So for now NATURAL needs to talk to two brokers, one on MF and one on Windows. We are hoping by installing Relay Manager NATURAL can communicate to Broker on Windows. We realize that Relay Manager goes away and the BKIMC and BKIMB stubs are upgraded to do TCP communication in future and will do this when all VB apps needing NATETB23 are rewritten. Does this sound feasible? Thanks.

I understand.
In this case you may consider to install only the EntireX Broker stubs of EXX 9.6. These stubs are compatible with older versions and supports transport method TCP as well as transport method NET. This means you can communicate from Natural with both EntireX Broker installations.
Please note that in case of transport method NET you must add the SVC number to the broker name if you are not using the default SVC, e.g. BKRnnn:SVCmmm:NET