Busy-on-Busy limits the calls to a group. The caller then hears the busy tone.

A maximum number of connection can be configured from which the group members can no longer be reached. Call forwardings (CFU) and multi-path call forwardings are still possible.

The maximum number of connections can also be configured dynamically. This ensures that the number of maximum connections is automatically adjusted to the number of registered group members so that the call is not put on hold.