I have a question about RFC mechanism in SAP R/3. I created an RFC and using this RFC destination I created a port for IDOC processing, and partner profiles. These IDOCs will be delivered to a third party sub-system SUN's Identitiy Manager. Sometimes these IDOCs show status 3 ( delivered to the port) and in SM58 they show in the queue with error "cannot register the RFC program on target system" something like that. When the adapter on the sub-system is started this queue will be cleared.
My question is whether the IDOCs are being pushed by SAP to the sub-system or the programs in the sub-system pull the IDOCs from SAP? When the sub-system is started sometimes the IDOCs that are created later are delivered and earlier IDOCs will be still in the queue.
How the RFC works? Is it works on UDP protocol?
Is there any status flag for IDOCs to indicate that they have been processed in SAP? Whether SAP sends only the processed IDOCs to the target system?
Thanks in advance