5.28.3.1 General

Port number for the PDU Session is assigned by the UPF during PDU session establishment. The port number for a PDU Session shall be reported to the SMF from the UPF and further stored at the SMF. The SMF provides the port number via PCF to the TSN AF or TSCTSF. TSN AF or TSCTSF maintains an association between the port number for the PDU Session and the DS-TT port MAC address (with Ethernet type PDU session) or IP address (applicable for TSCTSF only, with IP type PDU Session) of the UE. If a PDU session for which SMF has reported a port number to TSN AF or TSCTSF is released, then SMF informs TSN AF or TSCTSF accordingly. The port number for the PDU Session corresponds to the device side port of the 5GS bridge/router. When the device supports the DS-TT functionality, the port number represents the DS-TT port number corresponding to the given PDU Session.

NOTE 1: Port number can refer either to Ethernet port or PTP port. In Ethernet type PDU Sessions, it is assumed that the PTP port number is the same as the associated Ethernet port number.

When the DS-TT or the NW-TT functions are used, the 5GS shall support transfer of standardized and deployment-specific port management information transparently between TSN AF or TSCTSF and DS-TT or NW-TT, respectively inside a Port Management Information Container. NW-TT may support one or more ports. In this case, each port uses separate Port Management Information Container. 5GS shall also support transfer of standardized and deployment-specific user plane node management information transparently between TSN AF or TSCTSF and NW-TT, respectively inside a User Plane Node Management Information Container. Clause K.1 lists standardized port management information and user plane node management information, respectively.

If TSN AF is deployed, i.e. if 5GS is integrated with an IEEE TSN network, the port and user plane node management information is exchanged between CNC and TSN AF. The port management information is related to ports located in DS-TT or NW-TT. The user plane node management information container is related to 5GS bridge management.

If TSN AF is not deployed, the port and user plane node management information is exchanged between TSCTSF and DS-TT/NW-TT.

NOTE 2: The time synchronization parameters used in Port Management Information Container and User Plane Node Management Information Container are from IEEE Std 1588 [126], Edition 2019 and from IEEE Std 802.1AS [104]. Since the IEEE time synchronization data sets are not exposed, care needs to be taken when interoperating with devices supporting Edition 2008, IEEE Std 1588-2008 [107] (which can be the case when operating under the SMPTE profile, ST 2059-2:2015 [127]) and using a common management.

Exchange of port and user plane node management information between TSN AF or TSCTSF and NW-TT or between TSN AF or TSCTSF and DS-TT allows TSN AF or TSCTSF to:

• retrieve port management information for a DS-TT or NW-TT port or user plane node management information;
• send port management information for a DS-TT or NW-TT port or user plane node management information;
• subscribe to and receive notifications if specific port management information for a DS-TT or NW-TT port changes or user plane node management information changes.
• delete selected entries in the following data structures:
• "DS-TT port neighbour discovery configuration for DS-TT port" in UMIC using the DS-TT port number to reference the selected entry.
• "Stream Filter Instance Table" in PMIC using the Stream Filter Instance ID to reference the selected entry.
• "Stream Gate Instance Table" in PMIC using the Stream Gate Instance ID to reference the selected entry.
• "Static Filtering Entries table" in UMIC using the (MAC address, VLAN ID) pair to reference the selected entry.
• delete PTP Instances in a DS-TT port or NW-TT port using the PTP Instance ID to reference the selected entry as described in clause K.2.2.1.

Exchange of port management information between TSN AF or TSCTSF and NW-TT or DS-TT is initiated by DS-TT or NW-TT to:

• notify TSN AF or TSCTSF if port management information has changed that TSN AF or TSCTSF has subscribed for.

Exchange of user plane node management information between TSN AF or TSCTSF and NW-TT is initiated by NW-TT to:

• notify TSN AF or TSCTSF if user plane node management information has changed that TSN AF or TSCTSF has subscribed for.
• notify TSCTSF if time synchronization status information of UPF has changed that the TSCTSF has subscribed for.

Exchange of port management information is initiated by DS-TT to:

• provide port management capabilities, i.e. provide information indicating which standardized and deployment-specific port management information is supported by DS-TT.

TSN AF or TSCTSF indicates inside the Port Management Information Container or user plane node Management Information Container whether it wants to retrieve or send port or user plane node management information or intends to (un-)subscribe for notifications. If the TSN AF or TSCTSF has requested to receive notification of TSC management information and both SMF and UPF support direct reporting, the UPF may directly report TSC management information to the TSN AF or TSCTSF using Nupf_EventExposure_Notify.