Below is link to SAP website explaining all connection types to allow remote SAP support to customers.
https://support.sap.com/remote-support/connection-types.html
Tag: connection
SAP: RFC SM59 mass connection test
Tcode: RSRFCCHECK
This program let’s you test mass list of RFC connections. It means you can run a test for all RFC connections in your system, not only connection test, but logon test as well.