Section: 13.2.3.4 Modification policy
Content: The SEPP shall contain an operator-controlled policy that specifies which IEs can be modified by the IPX provider directly related to this particular SEPP. These IEs refer to the IEs after the sending SEPP has rewritten the message. Each PLMN-operator shall agree the modification policy with the IPX provider it has a business relationship with prior to establishment of an N32 connection. Each modification policy applies to one individual relation between PLMN-operator and IPX provider. To cover the whole N32 connection, both involved roaming partners shall exchange their modification policies. NOTE 1: In order to validate modifications for messages received on the N32-f interface, the operator’s roaming partners will have to know the overall modification policy. NOTE 2: Modification includes removal and addition of new IE. IEs therefore may not be present in the rewritten message. The IEs that the IPX is allowed to modify shall be specified in a list giving an enumeration of JSON paths within the JSON object created by the SEPP. Wildcards may be used to specify paths. This policy shall be specific per roaming partner and per IPX provider that is used for the specific roaming partner. The modification policy shall reside in the SEPP. For each roaming parter, the SEPP shall be able to store a policy for receiving. The following basic validation rules shall always be applied irrespective of the policy exchanged between two roaming partners: - IEs requiring encryption shall not be inserted at a different location in the JSON object.