What is a requirement for the virtual extension to work properly between master and slave configurations?

For a virtual extension to work properly between master and slave configurations, it is essential that it matches the master side virtual extension. This match is crucial because the virtual extension serves as a link between the two configurations, ensuring that calls can be routed correctly and that the settings align in a functional way.

When the virtual extension on the slave configuration mirrors the master's specifications, including parameters such as extension number and associated settings, it facilitates seamless communication and call handling interoperability. This synchronization ensures that users can access the system and maintain operational continuity without issues.

While it is important for the overall configurations to share certain aspects, such as SIP trunk connectivity and networking setups, the direct matching of the virtual extension on the master side is the focal requirement for efficient communication between master and slave setups. Other settings may vary, but the virtual extension's alignment is critical for proper functionality.