3CX Academy Advanced Certification Practice Test 2026 - Free 3CX Certification Practice Questions and Study Guide

The correct answer indicates that the Slave bridge must be registered behind the SBC (Session Border Controller). When using a master bridge in conjunction with the "Remote PBX uses SBC/Tunnel Connection" option, the architecture relies on the SBC for facilitating secure communication between the master and slave systems.

Registering the Slave bridge behind the SBC is essential because the SBC acts as a secure gateway that manages the traffic between the two PBXs. This placement ensures that all signaling and media are correctly routed while leveraging the SBC's capabilities for security and performance, such as handling NAT traversal and protecting against unauthorized access.

By positioning the Slave bridge behind the SBC, you also ensure that any specific configurations or policies implemented on the SBC are applied. This setup is particularly effective in scenarios where the Slave PBX is located in a different network environment that may have its own security constraints.

Options suggesting that the Slave bridge must be registered on the master PBX, at the local network, or in the cloud do not align with this architecture, as those configurations would not leverage the SBC's capabilities appropriately.