When you configure a shared extension in Cisco Configuration Professional, which two characteristics should be the same on both phones, so that the phones can successfully use a shared extension?…

Monitor mode is a busy lamp field feature used to observe the state of another extension and is not a configuration requirement for establishing a shared line.

MAC addresses are globally unique hardware identifiers assigned to individual phones and cannot be the same on two separate devices.

The ephone-dn is the IOS telephony configuration block that defines a directory number line; both phones must reference or be associated with the same ephone-dn so that call state such as busy, ringing, and connected is synchronized across them.

The directory number itself must be identical on both phones so that the shared extension represents the same dialable address to the call processing engine and to incoming callers.

User ID is an optional end-user association field in CUCM and is not evaluated by the shared-line mechanism when determining whether two phones share an extension.