6 Elementary procedures between TSN AF and NW-TT

24.5393GPP5G System (5GS)Network to TSN translator (TT) protocol aspectsRelease 17Stage 3TS

6.1 General

The TSN AF and NW-TT supports transfer of standardized and deployment-specific port management information, to manage the port used at the NW-TT. The TSN AF and NW-TT supports transfer of standardized and deployment-specific User plane node management information, to manage the NW-TT. The port management messages are included in the "PortManagementContainer" data type (as specified in 3GPP TS 29.512 [5B]) and the Port Management Information Container IE (as specified in 3GPP TS 29.244 [5A]) and the User plane node management messages are included in the "BridgeManagementContainer" data type (as specified in 3GPP TS 29.512 [5B]) and the User Plane node Management Information Container IE (as specified in 3GPP TS 29.244 [5A]). Both the port management messages and the User plane node management messages are transported using the N4 Session Level Reporting Procedure and the SM policy association modification procedure as specified in 3GPP TS 23.502 [3].

6.2 Procedures for port management service

6.2.1 TSN AF-requested port management procedure

6.2.1.1 General

The purpose of the TSN AF-requested port management procedure is to enable the TSN AF to:

a) obtain the list of port management parameters supported by the NW-TT;

b) obtain the current values of port management parameters at the NW-TT port;

c) set the values of port management parameters at the NW-TT port; or

d) subscribe to be notified by the NW-TT if the values of certain port management parameters change at the NW-TT port; or

e) unsubscribe to be notified by the NW-TT for one or more port management parameters.

6.2.1.2 TSN AF-requested port management procedure initiation

In order to initiate the TSN AF-requested port management procedure, the TSN AF shall:

a) encode the information about the port management parameters values to be read, the port management parameters values to be set, the port management parameters changes to (un)subscribe to and whether the TSN AF requests the list of port management parameters supported by the NW-TT in a port management list IE as specified in clause 9.2 and include it in a MANAGE PORT COMMAND message;

b) send the MANAGE PORT COMMAND message to the NW-TT via the PCF and the SMF as specified in 3GPP TS 23.502 [3]; and

c) start timer T100 (see example in figure 6.2.1.2.1).

Figure 6.2.1.2.1: TSN AF-requested port management procedure

6.2.1.3 TSN AF-requested port management procedure completion

Upon receipt of the MANAGE PORT COMMAND message, for each operation included in the port management list IE, the NW-TT shall:

a) if the operation code is "get capabilities", include the list of port management parameters supported by the NW-TT in the port management capability IE of the MANAGE PORT COMPLETE message;

b) if the operation code is "read parameter", attempt to read the value of the parameter at the NW-TT port, and:

1) if the value of the parameter at the NW-TT port is read successfully, include the parameter and its current value in the port status IE of the MANAGE PORT COMPLETE message; and

2) if the value of the parameter at the NW-TT port was not read successfully, include the parameter and associated port management service cause value in the port status IE of the MANAGE PORT COMPLETE message;

c) if the operation code is "selective read parameter", attempt to read the value of the selected sub-parameter(s) of the parameter at the NW-TT port, and:

1) if the value of the selected sub-parameter(s) at the NW-TT port is read successfully, include the parameter with the selected sub-parameter(s) and their current value in the port status IE of the MANAGE PORT COMPLETE message; and

2) if the value of the selected sub-parameter(s) at the NW-TT port was not read successfully, include the parameter and associated port management service cause value in the port status IE of the MANAGE PORT COMPLETE message;

d) if the operation code is "set parameter", attempt to set the value of the parameter at the NW-TT port to the value specified in the operation, and:

1) if the value of the parameter at the NW-TT port is set successfully, include the parameter and its current value in the port update result IE of the MANAGE PORT COMPLETE message; and

2) if the value of the parameter at the NW-TT port was not set successfully, include the parameter and associated port management service cause value in the port update result IE of the MANAGE PORT COMPLETE message;

NOTE 1: The value and status at the NW-TT of any optional sub-parameter not included in the parameter value field associated with operation code "set parameter" in the port management list IE of the MANAGE PORT COMMAND remains unchanged.

e) if the operation code is "subscribe-notify for parameter", store the request from the TSN AF to be notified of changes in the value of the corresponding parameter;

f) if the operation code is "selective subscribe-notify for parameter", store the request from the TSN AF to be notified of changes in the value of the corresponding sub-parameter(s) of the parameter;

g) if the operation code is "unsubscribe for parameter", delete the stored request from the TSN AF to be notified of changes in the value of the corresponding parameter, if any; and

h) if the operation code is "selective unsubscribe for parameter", delete the stored request from the TSN AF to be notified of changes in the value of the corresponding sub-parameter(s) of the parameter, if any; and

NOTE 2: If the operation code is "subscribe for parameter", the request from the TSN AF to be notified of changes in the value of the parameter is stored for each individual sub-parameter of the parameter. If the operation code is "selective unsubscribe for parameter", the stored requests from the TSN AF to be notified of changes in the value of sub-parameters are deleted only for the sub-parameters included in the parameter value field. If the operation code is "unsubscribe for parameter", the stored requests from the TSN AF to be notified of changes in the value of sub-parameters are deleted for all sub-parameters of the parameter.

i) send the MANAGE PORT COMPLETE to the TSN AF via the SMF and the PCF as specified in 3GPP TS 23.502 [3].

6.2.1.4 Abnormal cases in the TSN AF

The following abnormal cases can be identified:

a) T100 expired.

The TSN AF shall, on the first expiry of the timer T100, retransmit the MANAGE PORT COMMAND message and shall reset and start timer T100. This retransmission is repeated four times, i.e. on the fifth expiry of timer T35xx, the TSN AF shall abort the procedure.

6.2.1.5 Abnormal cases in the NW-TT

The following abnormal cases can be identified:

a) Transmission failure of the MANAGE PORT COMPLETE message indication from lower layers.

The NW-TT shall not diagnose an error and consider the TSN AF-initiated port management procedure complete.

NOTE: Considering that the TSN AF-initiated port management procedure complete as a result of this abnormal case does not cause the NW-TT to revert the execution of the operations included in the MANAGE PORT COMMAND message.

6.2.2 NW-TT-initiated port management procedure

6.2.2.1 General

The purpose of the NW-TT-initiated port management procedure is to notify the TSN AF of one or more changes in the value of port management parameters for which the TSN AF had requested to be notified of changes via the TSN AF-initiated port management procedure.

6.2.2.2 NW-TT-initiated port management procedure initiation

In order to initiate the NW-TT-initiated port management procedure, the NW-TT shall create an PORT MANAGEMENT NOTIFY message and shall:

a) include the port management parameters to be reported to the TSN AF with their current value in the port status IE of the PORT MANAGEMENT NOTIFY message;

b) start timer T300; and

c) send the PORT MANAGEMENT NOTIFY message to the TSN AF via the SMF and the PCF as specified in 3GPP TS 23.502 [3].

Figure 6.2.2.2.1: NW-TT-initiated port management procedure

6.2.2.3 NW-TT-initiated port management procedure completion

Upon receipt of the PORT MANAGEMENT NOTIFY message, the TSN AF shall:

a) create a PORT MANAGEMENT NOTIFY ACK message; and

b) send the PORT MANAGEMENT NOTIFY ACK message to the NW-TT via the PCF and the SMF as specified in 3GPP TS 23.502 [3].

Upon receipt of the PORT MANAGEMENT NOTIFY ACK message, the NW-TT shall stop timer T300.

6.2.2.4 Abnormal cases in the TSN AF

The following abnormal cases can be identified:

a) Transmission failure of the PORT MANAGEMENT NOTIFY ACK indication from lower layers.

The TSN AF shall not diagnose an error and consider the NW-TT-initiated port management procedure complete.

6.2.2.5 Abnormal cases in the NW-TT

The following abnormal cases can be identified:

a) T300 expired.

The NW-TT shall, on the first expiry of the timer T300, retransmit the PORT MANAGEMENT NOTIFY message and shall reset and start timer T300. This retransmission is repeated four times, i.e. on the fifth expiry of timer T300, the NW-TT shall abort the procedure.

6.3 Procedures for User plane node management service

6.3.1 TSN AF-requested User plane node management procedure

6.3.1.1 General

The purpose of the TSN AF-requested User plane node management procedure is to enable the TSN AF to:

a) obtain the list of user plane node management parameters supported at the NW-TT;

b) obtain the current values of user plane node management parameters at the NW-TT;

c) set the values of user plane node management parameters at the NW-TT; or

d) subscribe to be notified by the NW-TT if the values of certain user plane node management parameters change at the NW-TT; or

e) unsubscribe to be notified by the NW-TT for one or more user plane node management parameters.

6.3.1.2 TSN AF-requested User plane node management procedure initiation

In order to initiate the TSN AF-requested User plane node management procedure, the TSN AF shall:

a) encode the information about the user plane node management parameters values to be read, the user plane node management parameters values to be set, the user plane node management parameters changes to (un)subscribe to and whether the TSN AF requests the list of user plane node management parameters supported by the NW-TT in an User plane node management list IE as specified in clause 9.5B and include it in a MANAGE USER PLANE NODE COMMAND message;

b) send the MANAGE USER PLANE NODE COMMAND message to the NW-TT via the PCF and the SMF as specified in 3GPP TS 23.502 [3]; and

c) start timer T150 (see example in figure 6.3.1.2.1).

Figure 6.3.1.2.1: TSN AF-requested User plane node management procedure

6.3.1.3 TSN AF-requested User plane node management procedure completion

Upon receipt of the MANAGE USER PLANE NODE COMMAND message, for each operation included in the User plane node management list IE, the NW-TT shall:

a) if the operation code is "get capabilities", include the list of User plane node management parameters supported by the NW-TT in the User plane node management capability IE of the MANAGE USER PLANE NODE COMPLETE message;

b) if the operation code is "read parameter", attempt to read the value of the user plane node management parameter at the NW-TT, and:

1) if the value of the parameter at the NW-TT is read successfully, include the parameter and its current value in the User plane node status IE of the MANAGE USER PLANE NODE COMPLETE message; and

2) if the value of the parameter at the NW-TT was not read successfully, include the parameter and associated User plane node management service cause value in the User plane node status IE of the MANAGE USER PLANE NODE COMPLETE message;

c) if the operation code is "selective read parameter", attempt to read the value of the selected sub-parameter(s) of the user plane node management parameter at the NW-TT port, and:

1) if the value of the selected sub-parameter(s) at the NW-TT port is read successfully, include the parameter with the selected sub-parameter(s) and their current value in the User plante node status IE of the MANAGE USER PLANE NODE COMPLETE message; and

2) if the value of the selected sub-parameter(s) at the NW-TT port was not read successfully, include the parameter and associated User plane node management service cause value in the User plane node status IE of the MANAGE USER PLANE NODE COMPLETE message;

d) if the operation code is "set parameter", attempt to set the value of the user plane node management parameter at the NW-TT to the value specified in the operation, and:

1) if the value of the parameter at the NW-TT is set successfully, include the parameter and its current value in the User plane node update result IE of the MANAGE USER PLANE NODE COMPLETE message; and

2) if the value of the parameter at the NW-TT was not set successfully, include the parameter and associated User plane node management service cause value in the User plane node update result IE of the MANAGE USER PLANE NODE COMPLETE message;

NOTE 1: The value and status at the NW-TT of any sub-parameter not included in the parameter value field associated with operation code "set parameter" in the user plane node management list IE of the MANAGE USER PLANE NODE COMMAND remains unchanged.

e) if the operation code is "subscribe-notify for parameter", store the request from the TSN AF to be notified of changes in the value of the corresponding user plane node management parameter;

f) if the operation code is "selective subscribe-notify for parameter", store the request from the TSN AF to be notified of changes in the value of the corresponding selected sub-parameter(s) of the user plane node management parameter;

g) if the operation code is "unsubscribe for parameter", delete the stored request from the TSN AF to be notified of changes in the value of the corresponding user plane node management parameter, if any; and

h) if the operation code is "selective unsubscribe for parameter", delete the stored request from the TSN AF to be notified of changes in the value of the corresponding selected sub-parameter(s) of the user plane node parameter, if any; and

NOTE 2: If the operation code is "subscribe for parameter", the request from the TSN AF to be notified of changes in the value of the parameter is stored for each individual sub-parameter of the parameter. If the operation code is "selective unsubscribe for parameter", the stored requests from the TSN AF to be notified of changes in the value of sub-parameters are deleted only for the sub-parameters included in the parameter value field. If the operation code is "unsubscribe for parameter", the stored requests from the TSN AF to be notified of changes in the value of sub-parameters are deleted for all sub-parameters of the parameter.

i) send the MANAGE USER PLANE NODE COMPLETE to the TSN AF via the SMF and the PCF as specified in 3GPP TS 23.502 [3].

6.3.1.4 Abnormal cases in the TSN AF

The following abnormal cases can be identified:

a) T150 expired.

The TSN AF shall, on the first expiry of the timer T150, retransmit the MANAGE USER PLANE NODE COMMAND message and shall reset and start timer T150. This retransmission is repeated four times, i.e. on the fifth expiry of timer T150, the TSN AF shall abort the procedure.

6.3.1.5 Abnormal cases in the NW-TT

The following abnormal cases can be identified:

a) Transmission failure of the MANAGE USER PLANE NODE COMPLETE message indication from lower layers.

The NW-TT shall not diagnose an error and consider the TSN AF-initiated User plane node management procedure complete.

NOTE: Considering that the TSN AF-initiated User plane node management procedure complete as a result of this abnormal case does not cause the NW-TT to revert the execution of the operations included in the MANAGE USER PLANE NODE COMMAND message.

6.3.2 NW-TT-initiated User plane node management procedure

6.3.2.1 General

The purpose of the NW-TT-initiated User plane node management procedure is to notify the TSN AF of one or more changes in the value of User plane node management parameters for which the TSN AF had requested to be notified of changes via the TSN AF-initiated User plane node management procedure.

6.3.2.2 NW-TT-initiated User plane node management procedure initiation

In order to initiate the NW-TT-initiated User plane node management procedure, the NW-TT shall create a USER PLANE NODE MANAGEMENT NOTIFY message and shall:

a) include the User plane node management parameters to be reported to the TSN AF with their current value in the User plane node status IE of the USER PLANE NODE MANAGEMENT NOTIFY message;

b) start timer T350; and

c) send the USER PLANE NODE MANAGEMENT NOTIFY message to the TSN AF via the SMF and the PCF as specified in 3GPP TS 23.502 [3].

Figure 6.3.2.2.1: NW-TT-initiated User plane node management procedure

6.3.2.3 NW-TT-initiated User plane node management procedure completion

Upon receipt of the USER PLANE NODE MANAGEMENT NOTIFY message, the TSN AF shall:

a) create a MANAGE USER PLANE NODE MANAGEMENT NOTIFY ACK message; and

b) send the MANAGE USER PLANE NODE MANAGEMENT NOTIFY ACK message to the NW-TT via the PCF and the SMF as specified in 3GPP TS 23.502 [3].

Upon receipt of the USER PLANE NODE MANAGEMENT NOTIFY ACK message, the NW-TT shall stop timer T350.

6.3.2.4 Abnormal cases in the TSN AF

The following abnormal cases can be identified:

a) Transmission failure of the USER PLANE NODE MANAGEMENT NOTIFY ACK indication from lower layers.

The TSN AF shall not diagnose an error and consider the NW-TT-initiated User plane node management procedure complete.

6.3.2.5 Abnormal cases in the NW-TT

The following abnormal cases can be identified:

a) T350 expired.

The NW-TT shall, on the first expiry of the timer T350, retransmit the USER PLANE NODE MANAGEMENT NOTIFY message and shall reset and start timer T350. This retransmission is repeated four times, i.e. on the fifth expiry of timer T350, the NW-TT shall abort the procedure.

b) Transmission failure of the USER PLANE NODE MANAGEMENT NOTIFY COMPLETE message indication from lower layers.

The NW-TT shall not diagnose an error and consider the NW-TT-initiated User plane node management procedure complete.