The RPC system ensures that each RPC call is either received by the business layer of the application in its entirety, or not at all.
Each RPC call is a fairly coarse-grained object: there is a lot of overhead, and a lot of data is transferred. LISS does not have any "incremental" calls.
Each SIS or satellite system can choose whether to process each row in an RPC table as a transaction, or whether the table as a whole is processed as a transaction. LISS does not recommend either approach.