CPN (Calling Party Number) substitution is typically used to show the customer's corporate name and number for all outgoing calls to the public network. The 3300 ICP provides two types of CPN substitution: DID-based and DN-based.
DID-based substitution is used for individual DID numbers or ranges of DID numbers and applies to calls over embedded PRI/DPNSS trunks and embedded BRI trunks ("T" interface only).
DN-based substitution is done at the directory number level but only over embedded PRI/DPNSS trunks.
You can program both types of substitution on the same system, or within a cluster or network, with priority given to DN-based substitution.
DN-based CPN substitution is only supported for PRI trunks. It is not supported for SIP trunks.
When using DN-based CPN substitution in a network with multiple public network gateways, the gateways must all connect to Central Offices that allow the programmed calling party numbers. Some PRI networks will only allow certain ranges of CPNs and may drop a call if the CPN is disallowed.
The CPN programmed for DN-based substitution should allow uncompleted calls to return to the call originator or to some other number such as the attendant.
If this feature is used in a geographically-distributed network of switches, it is possible that although outgoing calls may bypass tolls, such calls returned to extensions provisioned with DN-based CPN Substitution may not.
The following rules apply to CPN delivery to the public network for forwarded/rerouted calls:
When an internal call from an extension (Party A) which is provisioned with DN-based CPN is call forwarded to the public network via another extension (Party B), the CPN Substitution programmed for Party A will be passed to the public network not the CPN Substitution programmed for Party B. If Party A has both DID-based and DN-based CPN substitution programmed, the DID-based substitution will be followed.
When
Party A transfers an external call
Support for DN-based CPN substitution requires upgrades to 3300 ICP Release 9.0 UR1 or later on each of the following:
Calling Party Switch
Gateway Switch to the Public Network
PRI Card load.
To program DID-Based CPN Substitution
In the CPN Substitution form at the switch hosting the DN (or at either the host or secondary for a resilient DN), specify which substitutions to apply on a PRI link.
Use the DID Ranges for CPN Substitution form to associate DID numbers with the CPN substitution digits programmed in the CPN Substitution form.
To program DN-Based CPN Substitution
In the Associated DN Assignment form
Enter the directory number on which to perform CPN substitution
Set the Associated Type to CPN Substitution
Enter the substitution number.
In the Class of Service Options Assignment form
Set Non-Prime Public Network Identity to 'Yes' to implement substitution on calls made from non-prime lines.
For both substitution types:
In
the Protocol
Assignment form, specify which number to use in CPN substitution for
inbound PRI calls forwarded to the public network
Note: These digits are sent whether the CO See Central Office or Telephone Exchange. allows them or not. It is the System Administrator's responsibility to ensure that the digits programmed in the Associated Digits field of the Associated DN Assignment form are acceptable to the CO.
None.