PO-SO Creation Idoc Partner & Parameters Maintenance

Hello Idoc Network,

The answer to this can clear many things and the question is a bit detailed so please bear with me on this

I am currently working on a PO-SO creator Idoc and simultaneously looking at Outbound/Inbound parameter maintenance

I have a PO which creates a SO in the same client, the SO is getting creating successfully but my confusion lies elsewhere.

On checking the outbound Idoc I see that it is sent to the vendor say 123 (PO raised to the vendor 123) but when I see the Parameters of this vendor 123 I see that the port and the message type is maintained in vendors outbound parameters and not inbound. This is a bit misleading for newcomers as they would definitely think that since 123 is the recipient (incoming towards 123) of the Idoc the information like the Port and message type would be maintained in its inbound parameters of 123(LI) but there is no option for port in Inbound parameters then after that I looked at the wording “receiver port” and then it all cleared the confusion for me

But the confusion grew even more when the outbound Idoc had a sender information which is of course the current client (say PR1 or PO sender system) and was maintained with a port. A port?? I went and checked the outbound parameters (since inbound have no ports) of the sender Partner number (PR1 in LS) and found no ports, so where did the port get picked up for this Idoc ?

I was hoping to find port field in SCC4 since the LS the client is connected to is maintained there.

Ahmed