Let me explain this from a carrier perspective, which may clarify the ambiguity of terms.
For POTS Service (home or business) single lines the ANI/CPN/CallerID are the same number per line. If you have multiple lines then it can change.
ANI- Automatic Number Identifier: This is the number provided to the called party. ie: Caller ID inbound received number. This number can be derived from a number of sources
BTN- Billed To Number: This is the number delivered to LD carriers, other LEC/CLEC's as an identifier for all billing purposes. This number is fixed and un-changable except on a Carrier level.
CBN- Customer Billing Number: This number is the main billing number for the customer location, it may, or may not, be the same as the BTN. This is equivalent to the main number on a multi-line hunt group and is usually Site Specific, and is usually, BUT NOT ALWAYS, used for 911 services. This may, or may not be, the Listed Directory Number (LDN) for a customer.
LDN- Listed Directory Number: This is the Directory published number for a customer. It may be the BTN, and the CBN as well. It could be an old published number for a customer that has been re-pointed to a new DID or ISDN trunk group.
CPN- Customer Provided Number: This is the Customer Outbound "Caller ID" provided to the called party. It is usually the same as the CBN, if the Carrier is not accepting different CPN information from the customers switch.
If the customer has ISDN-PRI service, and the carrier is accepting "CPN", then the CPN information to the CALLED PARTY in the form of "CallerID" can be modified using the ISDN Public tables and the appropriate changes to the ISDN Trunk Group.
A word of warning here, SOME carrier information is superceeded by CPN, INCLUDING 911! If you send individual users extension numbers (DN's) with the Base ISDN PUBLIC tables then you must have your carrier notify 911 Services to include your full DN range, otherwise they will receive a number as unidentified location. It is wise to test 911 service on a new or changed carrier or service type. You will notice that newer switch releases have more "granularity" with respect to 911 services, be wise identify.
I recently had to work with a carrier and client on a failed 911 response; a) the ARS tables were incorrect. b) when the ARS was corrected, and retested, the address was identified as being the carriers serving Central Office!!