thanks for the answer. The issue with this topic is, that as far as I understand we are only able to first accept the connection, and afterwards reject / reset all additional ones. This is what we are currently doing, but our customer does have problems, if it is first signalized with OK, and afterwards we do a reset (the customer has an issue with the fault handling).
What looks strange to me: If you set this value to '1' it works as described:
The first connection is accepted by our application. If the client requests another connection this is accepted bt not handled (at least it is in the queue of the network stack). If we close the first connection, we get the second one, and all data which is sent to it in the meantime. So I thought I can set this value to '0', but then the first connection is not accepted anyhow. I tried to have a solution, to build up an own internal connection after the first one is established,but this could be to much risk from timing point of view.
So summarize: At least it seems, that something is done with this parameter, but only if it is > 0.