[SR-Users] Request documentation of Path Flow of Kamailio

Dear Sir/Madam, I am a student, doing a dissertation about the performance of VPN throughout VoIP Services whereas I decided to configure Kamailio with Siremis Web User Interface on Linux 18.04LTS. I also am using GNS3 as I am trying to connect the server with 3 different routers as a form of sites with different network. What am trying to do is that from the SIP I would try to call from one site to another and see the performance however I need some informations of the Kamailio Server. I need the path communication of how Kamailio works meaning the traffic, protocols being used and these are multicast or unicast when transfer from one site to another. Is this information available somewhere as I seem not to find it anywhere which is why I'm sending you to find out if you have these documentations that I request. I hope to hear from you soon and thanks. Sincerely, Daniel Cassar