A Session Border Controller (SBC) for Teams allows organisations deal with SIP trunking securely

https://www.scribd.com/document/877144704/Grasping-Direct-Path-and-Its-Relationship-with-Session-Border-Controllers-in-Groups-220104

A Session Border Controller (SBC) for Teams is helping groups cope with SIP trunking securely, facilitating improved call leadership and cutting back latency problems.