What feature allows customization of outbound caller IDs for specific extensions?

The feature that allows for the customization of outbound caller IDs for specific extensions is Caller ID Configuration. This function is specifically designed to manage how the caller ID presents itself when a call is made from a particular extension. With Caller ID Configuration, administrators can assign different outbound caller IDs to each extension, providing flexibility for branding or compliance purposes.

This means that when users make outbound calls, the number displayed to the recipient can be tailored to reflect either the company's main number, a department-specific number, or even the individual extension, depending on the configuration set up for that extension. This is particularly useful for organizations that want to maintain a consistent corporate image or navigate through regulatory requirements around caller identification.

Other options, while related to calling features, do not offer the specific functionality for customizing outbound caller IDs at the extension level. Outbound Rules pertain more to the conditions under which calls are made, such as routing based on the dialed number or time of day. Extension Settings deal with overall preferences and parameters for an extension but not specifically for caller ID customization. SIP Trunk Settings primarily focus on the configuration of the trunk itself for making VoIP calls and do not directly relate to individual caller ID management for extensions.