Broker v8 and RPC Server v6 - Parameter for 5MB Messages

We are using .NET to communicate through the Broker (V8.0.0) and the RPC Server (V6.2.3.1) to Adabas data located on the mainframe.

Tests with up to 5MB XML data showed that we ran into buffer problems and the documentation doesn’t discuss clearly the dependencies between broker and RPC buffers.

The documentation also doesn’t point out whether RPCSIZE=5000 is in bytes or in K (*1024)

For example
RPCSIZE should be lower or equal to the message buffer in EXX
MAXBUFF should be lower than RPCSIZE-34 (so our tests)
MAXBUF=4992 AND RPCSIZE=5026 LEADS TO ERROR 7

Questions:
Where can we get more information about the different buffers and their communication?
How should we set our buffers to send 5MB data?
Is there a training class available?

Thanks,
Dieter Storr

MAXBUFF and RPCSIZE are documented in:

http://techcommunity.softwareag.com/ecosystem/documentation/natural/nat424mf/parms/maxbuff.htm

http://techcommunity.softwareag.com/ecosystem/documentation/natural/nat424mf/parms/rpcsize.htm