3GPP TS 23501-h20 中英文对照 | 5.29.4 User Plane handling

Posted 2021-12-29 COCOgsta

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5.29.4 User Plane handling

User Plane management as defined for 5GS in clause 5.8 is applicable to 5G LAN-type services with the following clarifications:

第5.8条中为5GS定义的User Plane管理适用于5G LAN-type的服务，具体说明如下：

- There are three types of traffic forwarding methods allowed for 5G VN communication:

-5G VN通信允许三种类型的流量转发方法：

- N6-based, where the UL/DL traffic for the 5G VN communication is forwarded to/from the DN;

-N6-based，其中5G VN通信的UL/DL业务被转发到DN或从DN转发；

- N19-based, where the UL/DL traffic for the 5G VN group communication is forwarded between PSA UPFs of different PDU sessions via N19. N19 is based on a shared User Plane tunnel connecting PSA UPFs of a single 5G VN group.

-N19-based，其中5G VN组通信的UL/DL流量通过N19在不同PDU会话的PSA UPF之间转发。N19基于连接单个5G VN组的多个PSA UPF的共享User Plane隧道。

- Local switch, where traffic is locally forwarded by a single UPF if this UPF is the common PSA UPF of different PDU Sessions for the same 5G VN group.

-本地交换，如果该UPF是同一5G VN组的不同PDU会话的公共PSA UPF，则流量由单个UPF本地转发。

- The SMF handles the user plane paths of the 5G VN group, including:

-SMF处理5G VN组的用户平面路径，包括：

- The SMF may prefer to select a single PSA UPF for as many PDU sessions (targeting the same 5G VN group) as possible, in order to implement local switch on the UPF.

-SMF可能更愿意为尽可能多的PDU会话（针对相同的5G VN组）选择单个PSA UPF，以便在UPF上实现本地切换。

- (if needed) Establishing N19 tunnels between PSA UPFs to support N19-based traffic forwarding.

-（如果需要）在PSA UPF之间建立N19隧道，以支持基于N19的流量转发。

- For Ethernet PDU Session, the SMF may instruct the UPF(s) to classify frames based on VLAN tags, and to add and remove VLAN tags, on frames received and sent on N6 or N19 or internal interface ("5G VN internal"), as described in clause 5.6.10.2.

-对于Ethernet PDU Session，SMF可指示UPF根据VLAN标记对帧进行分类，并在N6或N19或内部接口（“5G VN内部”）上接收和发送的帧上添加和删除VLAN标记，如第5.6.10.2条所述。

NOTE 1: For handling VLAN tags for traffic on N6, TSP ID could also be used as described in clause 6.2.2.6 of TS 23.503 [45].

注1：如TS 23.503[45]第6.2.2.6条所述，为了处理N6上流量的VLAN标记，也可以使用TSP ID。

Further description on User Plane management for 5G VN groups is available in clause 5.8.2.13.

关于5G VN组User Plane管理的进一步说明，请参见第5.8.2.13条。

When N6-based traffic forwarding is expected, after creation of a 5G VN group the AF can influence the traffic routing for all the members of the 5G VN group, by providing information identifying the traffic, DNAI(s) suitable for selection and an optional indication of traffic correlation together with a 5G VN External Group ID identifying the 5G VN group in an AF request sent to the PCF, as described in clause 5.6.7. If the optional indication of traffic correlation is provided, it means the PDU sessions of the 5G VN group member UEs should be correlated by a common DNAI in the user plane for the traffic. The PCF transforms the AF request into policies that apply to PDU Sessions of the 5G VN group and sends the policies to the SMF. According to the policies, the SMF (re)selects DNAI(s) for the PDU Sessions and configures their UP paths to route the traffic to the selected DNAI(s). If the policies include the traffic correlation indication, the SMF (re)selects a common DNAI for the PDU Sessions so that the traffic of the 5G VN group is routed to the common DNAI.

当预期基于N6的业务转发时，在创建5G VN组之后，AF可以通过提供识别流量、DNAI的信息来影响5G VN组的所有成员的流量路由，如第5.6.7条所述。适用于选择和可选指示流量相关性，以及5G VN External Group ID，用于识别发送至PCF的AF请求中的5G VN组。如果提供了流量相关性的可选指示，则意味着5G VN组成员UE的PDU会话应通过用户平面中的公共DNAI来关联流量。PCF将AF请求转换为适用于5G VN组PDU Session的策略，并将策略发送给SMF。根据策略，SMF（重新）为PDU Session选择DNAI，并配置其UP路径以将流量路由到所选DNAI。如果策略包括流量相关指示，则SMF（重新）为PDU Session选择公共DNAI，以便将5G VN组的流量路由到公共DNAI。

NOTE 2: When receiving a new PDU session establishment request for a 5G VN group, to avoid unnecessary N19 tunnels between UPFs, SMF can check previously selected UPFs for the same 5G VN group, and decide whether a previously selected UPF could serve the requested PDU session.

注2：当接收到5G VN组的新PDU会话建立请求时，为了避免UPF之间不必要的N19隧道，SMF可以检查相同5G VN组先前选择的UPF，并决定先前选择的UPF是否可以服务于请求的PDU会话。

NOTE 3: N19 tunnel(s) can be established between a new UPF and other UPF(s) that belongs to a 5G VN group when the new UPF is selected for the 5G VN group during PDU session establishment. The N19 tunnel(s) to a UPF can be released during or after PDU session release when there is no more PDU sessions for a 5G VN group in that UPF. Establishment or release of the N19 tunnels at the UPF is performed within a group-level N4 Session.

注3：当在PDU会话建立期间为5G VN组选择新UPF时，可以在新UPF和属于5G VN组的其他UPF之间建立N19隧道。当5G VN组在UPF中没有更多PDU会话时，可以在PDU会话释放期间或之后释放到UPF的N19隧道。UPF中N19隧道的建立或释放在组级N4会话中执行。