Here is a visual guide to quickly test the connectivity between an SAP ECC system and the Ariba Network, when planning to use Direct Connectivity. I found this was an easy way to discover connectivity issues early on, when implementing the SAP Business .
Mediated Connectivity using SAP PI as the mediator and will be a part of a different post.
Import the Ariba Network Server certificate - STRUST
Export the certificate from https://buyer.ariba.com using internet explorer (click on the lock icon, details tab, export. Save as Base-64, X509)
Import in tr. STRUST under node SSL System Client SSL Client (Anonymous)
And Click the save button
Make sure the HTTPS service is active -> tr. SMICM
Click the Services button
Menu: Service -> Create
Fill in the HTTPS configuration
Create the RFC connection - SM59
Test the RFC Connection - SM59
Open the created connection in step 3
Click Connection Test
Expect the HTTP 200 response
Restart the ICM -> tr. SMICM, Menu: Administration -> ICM -> Restart -> Yes