Say if I want to run a de-register or say a successful call : where I want to see INVITE and 183 Ringing messages etc. How can I run those scenarios with my Open IMS SIPp?
You need to configure the Sipp xml file according to your scenario. You can find many configurations on the internet. For instance, see the attached link for authenticated outgoing call.
Of course, in order to test the scenario call this xml file, and make sure that your core can understand , handle and then send the appropriate answers expected by the UAC and indicated by the tag in your XML file.
I think I got the answer to this. So all the scenarios file are automatically executed once all the registrations are complete. I configured my manager.xml file to restrict to just 2000 registrations and after that the ims_uac, ims _msgs, ims_dereg all the scenarios are automatically executed