How do I tell which number a call has come in?

When an operator who needs to selectively answer incoming calls for different company numbers, belonging to different companies or departments, a signal is required to help him understand which number has been called.
To do this you can use the GUI.
In practice, when the incoming call for a company number must be routed, it is sufficient to create different response groups (one for each company or department) with the same operators inside and with a name that identifies the company.
Using the routing rules, route the various company numbers to the relevant group.
When the call for the group comes in, the operator, observing the GUI, will read which group was called and therefore will understand which company number was dialed by the caller.