SAP PI connectivity deals with the connectivity of source or target system with the integration server. This connectivity deals with the exchange of messages with integration server. The message format to be exchanged should be in SAP PI protocol format or an adapter should be used to convert an external format to SAP PI specific format.
After upgrading to PI 7.3x, you notice during the configuration of RFC communication channel in Integration Directory, that in the "RFC Metadata Repository Parameter" section, you need to maintain "Logon User" and "Logon Password" despite the Authentication Mode: Secure Network Connection for RFC
Transaction MDMAPIC -> RFC Destination -> Connection Test You are getting the mentioned or similar one You cannot find MDM Server in the SMGW -> Logged on clients list
9. Create the Jco RFC destination by choosing Finish. Result. The Jco RFC destination creates a number of u201CServer Countu201D RFC server threads on your AS Java. These RFC servers register at the RFC Gateway specified. You may configure multiple ABAP systems to connect to these RFC servers.