Section: 13.2.3.6 Precedence of policies in the SEPP
Content: This clause specifies the order of precedence of data-type encryption policies and modification policies available in a SEPP. In increasing order of precedence, the following policies apply for a message to be sent on N32: 1. The set of default rules specified in the present specification: - For the data-type encryption policy, the rules on data-types that are mandatory to be encrypted according to clause 5.9.3.3. - For the modification policy, the basic validation rules defined in clause 13.2.3.4. 2. Manually configured policies: - For the data-type encryption policy: rules according to clause 13.2.3.2, on a per roaming partner basis. - For the modification policy: rules according to clause 13.2.3.4, per roaming partner and per IPX provider that is used for the specific roaming partner. NOTE 1: It is assumed that operators agree both data-type encryption and modification policy in advance, for example as part of their bilateral roaming agreement. The protection policies exchanged via N32-c during the initial connection establishment only serve the purpose of detecting possible misconfigurations. NOTE 2: It is assumed that the default rules and manually configured policies do not overlap or contradict each other. The manually configured policies are used to extend the protection by the default rules in the present document and are applied on top of them. When a SEPP receives a data-type encryption or modification policy on N32-c as specified in clause 13.2.2.2, it shall compare it to the one that has been manually configured for this specific roaming partner and IPX provider. If a mismatch occurs for one of the two policies, the SEPP shall perform one of the following actions, according to operator policy: - Send the error message as specified in TS 29.573[ 5G System; Public Land Mobile Network (PLMN) Interconnection; Stage 3 ]  [73], clause 6.1.4.3.2, to the peer SEPP. - Create a local warning.