Traditional PSTN networks use tie line connectors between two PBX systems. Which method is used by a VoIP router positioned between two PBX systems to establish a connection and route a voice call? Use credible Internet resources of your choice as well as the study materials to analyze the steps involved to set up a VoIP call, and describe the components and protocols involved in the process. Describe the functionality of gateways and routers, IP PBX systems, and IP telephones. Describe voice port connection modes on Cisco routers. Analyze the process to set up a VoIP call across a VoIP network using SS7, softswitch, media gateways, and PSTN switch.