Section: 5.6.10.1 Support of IP PDU Session type
Content: The IP address allocation is defined in clause 5.8.1 The UE may acquire following configuration information from the SMF, during the lifetime of a PDU Session: - Address(es) of P-CSCF(s); - Address(es) of DNS server(s). - If the UE indicates support of DNS with security as defined in TS 33.501[ Security architecture and procedures for 5G System ]  [29] to the network in PCO and the network wants to enforce the use of DNS with security, the configuration information sent by the SMF via PCO may also include the corresponding DNS server security information as specified in TS 24.501[ Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3 ]  [47] and TS 33.501[ Security architecture and procedures for 5G System ]  [29]. - the GPSI of the UE. The UE may acquire from the SMF, at PDU Session Establishment, the MTU that the UE shall consider, see clause 5.6.10.4. The UE may provide following information to the SMF during the lifetime of a PDU Session: - an indication of the support of P-CSCF re-selection based on procedures specified in TS 24.229[ IP multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP); Stage 3 ]  [62] (clauses B.2.2.1C and L.2.2.1C). - PS data off status of the UE. NOTE 2: An operator can deploy NAT functionality in the network; the support of NAT is not specified in this release of the specification, though UPF can expose mapping between public and private IP addresses.