RFC Call - 'Expire Time-out' not allowed?

Hello,

Why do ‘Expire Timeout’ settings only apply to open but unsused RFC connections? - The settings are located in the ‘Connection Manager Properties’ of a SAP Adaptor (wM)

I received the below mail from SAG on this issue but did not get any indepth explanation.

I do not understand why wM cannot drop an RFC connection (whether unused or not). Can any one explain please?

mail from SAG…
Transactional RFC calls (with TID provided) are asynchronous. In actual fact, both sync and async RFCs don’t allow a time-out. The time-out parameters of the SAP Adapter only apply for open but unused connections. This is a limitation within SAP Jco.