Resolution:
The "callMB", "mbRpcClientRef", "mbOperationRef" tags in the
SAPadapter, provide support for running  MessageBroker in embedded
mode.  The SAP Adapter with it's features to invoke MessageBroker
"in-proc", will allow you to call a prebuilt MessageBroker sheet or
make reference to an MBRPCClient or MBRPCOperation. You will
still need MessageBroker to design your worksheet with the necessary
plugins and transformation logic.
By using embedded MB feature you are using MessageBroker in the
'non-gui' or 'in-proc' mode i.e you dont need to start MessageBroker as
a separate process at *runtime*, when you use the embedded
MB feature .
We recommend that you *limit* the use of MessageBroker in embedded
mode. Since you will need to design your MessageBroker worksheet for
use with SAP Adapter during the design & development phase;
the embedded MessageBroker feature should be made use of ONLY if
performance improvement warrants it.