学习5G知识，势必要去阅读相关的技术标准，而纯英文的标准协议对于初学者来说是个门槛。

个人在学习5G标准3GPP TS 29244-g30过程中，也发现google的机器翻译实在晦涩难懂，所以个人在借助百度翻译（中国人更懂中文）的同时，人工对每句话进行了校对。

在自己学习的同时，也将翻译内容分享给给广大网友。由于个人能力有限，翻译不到位的地方还请各位网友们指正。

5.2.1 General

The packet forwarding scenarios supported over the Sxa, Sxb and Sxc reference points are specified in 3GPP TS 23.214 [2].

3GPP TS 23.214[2]中规定了在Sxa、Sxb和Sxc参考点上支持的分组转发场景。

The packet forwarding scenarios supported over the N4 reference point are specified in 3GPP TS 23.501 [28] and 3GPP TS 23.502 [29].

在3GPP TS 23.501[28]和3GPP TS 23.502[29]中规定了在N4参考点上支持的分组转发场景。

The CP function controls the packet processing in the UP function by establishing, modifying or deleting PFCP Session contexts and by provisioning (i.e. adding, modifying or deleting) PDRs, FARs, QERs, URRs, BAR and/or MAR or by activating/deactivating pre-defined PDRs, FARs, QERs, URRs, per PFCP session context, whereby a PFCP session context may correspond:

CP功能通过建立、修改或删除PFCP会话上下文以及通过提供PDRs、FARs、QERs、URRs、BAR和/或MAR或者通过激活/停用每个PFCP会话上下文的pre-defined PDRs、FARs、QERs、URRs来控制UP功能中的包处理，其中PFCP会话上下文可以对应于：

- for EPC, to an individual PDN connection, a TDF session, or a standalone session not tied to any PDN connection or TDF session used e.g. for forwarding Radius, Diameter or DHCP signalling between the PGW-C and the PDN.

-对于EPC，PFCP会话可对应单个PDN连接、TDF会话或独立会话，而不是与任何PDN连接或TDF会话相关联，例如用于在PGW-C和PDN之间转发Radius、Diameter或DHCP信令。

- for 5GC, to an individual PDU session or a standalone PFCP session not tied to any PDU session.

-对于5GC，PFCP会话可对应单个PDU会话，或者一个没有绑定任何PDU会话的独立PFCF会话。

Each PDR shall contain a PDI, i.e. one or more match fields against which incoming packets are matched, and may be associated to the following rules providing the set of instructions to apply to packets matching the PDI:

每个PDR应包含一个PDI，即一个或多个匹配字段，输入数据包与之匹配，并可与提供应用于匹配PDI的数据包的指令集的以下规则相关联：

- one or more FARs, which contains instructions related to the processing of the packets as follows:

-一个或多个FAR，其中包含与处理分组相关的指令，如下所示：

- an Apply Action parameter, which indicates whether the UP function shall forward, duplicate, drop or buffer the packet with or without notifying the CP function about the arrival of a DL packet, or whether the UP function shall accept or deny UE requests to join an IP multicast group;

-Apply Action参数，表示UP功能是否转发、复制、丢弃或缓冲数据包，是否通知CP功能DL数据包的到达，或者UP功能是否接受或拒绝UE加入IP组播组的请求；

- forwarding, buffering and/or duplicating parameters, which the UP function shall use if the Apply Action parameter requests the packets to be forwarded, buffered or duplicated respectively. These parameters may remain configured in the FAR regardless of the Apply Action parameter value, to minimize the changes to the FAR during the transitions of the UE between the idle and connected modes. The buffering parameters, when present, shall be provisioned in a BAR created at the PFCP session level and referenced by the FAR.

-转发、缓冲和/或复制参数，如果Apply Action参数请求分别转发、缓冲或复制数据包，UP功能应使用这些参数。这些参数可以保持在FAR中配置，而不管Apply Action参数值如何，以最小化UE在空闲和连接模式之间的转换期间对FAR的改变。缓冲参数（如果存在）应在PFCP会话级别创建的BAR中提供，并由FAR引用。

NOTE 1: Buffering refers here to the buffering of the packet in the UP function. The UP function is instructed to forward DL packets to the CP function when applying buffering in the CP function. See clause 5.3.1.

注1：此处的缓冲是指在UP功能中对数据包的缓冲。当在CP功能中应用缓冲时，指示UP功能将DL数据包转发到CP功能。参见第5.3.1节。

- zero, one or more QERs, which contains instructions related to the QoS enforcement of the traffic;

-零个、一个或多个QER，其中包含与流量的QoS实施相关的指令；

- zero, one or more URRs, which contains instructions related to traffic measurement and reporting.

-零，一个或多个URR，其中包含与流量测量和报告相关的说明。

- zero or one MAR, which contains instructions related to Access Traffic Steering, Switching and Splitting (ATSSS) for the downlink traffic of a Multi-Access (MA) PDU session. See clause 5.2.7.

-零或一个MAR，其中包含与Multi-Access PDU会话的下行链路流量的Access Traffic Steering、Switching和Splitting相关的指令。

NOTE 2: A downlink PDR can be associated with two FARs for a N4 session established for a MA PDU session as a MAR contains two FARs for 3GPP and non-3GPP respectively.

注2：下行链路PDR可以与为MA PDU会话建立的N4会话的两个FAR相关联，因为MAR分别包含用于3GPP和非3GPP的两个FAR。

A FAR, a QER, a URR and a MAR shall only be associated to one or multiple PDRs of the same PFCP session context.

FAR、QER、URR和MAR仅应与同一PFCP会话上下文中的一个或多个PDR关联。

The QoS Enforcement Rule Correlation ID shall be assigned by the CP function to correlate QERs from multiple PFCP session contexts. For instance, the enforcement of APN-AMBR in the PGW-U shall be achieved by setting the same QoS Enforcement Rule Correlation ID to the QERs from different PFCP sessions associated with all the PDRs corresponding to the non-GBR bearers of all the UE's PDN connections to the same APN. The QERs that are associated to the same QoS Enforcement Rule Correlation ID in multiple PFCP sessions shall be provisioned, with the same QER contents, in each of these PFCP sessions. The QoS Enforcement Rule Correlation ID shall be only used to enforce the APN-AMBR when the UE is in EPC, it may be provided by the CP function over N4 to the UP function for a PDU session may move to EPC in a later stage.

QoS Enforcement Rule Correlation ID应由CP功能分配，以关联来自多个PFCP会话上下文的QER。例如，PGW-U中的APN-AMBR的实施应通过将相同的QoS Enforcement Rule Correlation ID设置到来自与所有PDR相关联的不同PFCP会话的QER来实现，该PDR对应于与相同APN的所有UE的PDN连接的non-GBR承载。在多个PFCP会话中与相同的QoS Enforcement Rule Correlation ID相关联的QER应在这些PFCP会话中的每一个中以相同的QER内容来提供。QoS Enforcement Rule Correlation ID应仅用于在UE处于EPC时实施APN-AMBR，它可由CP功能通过N4提供给UP功能，以便PDU会话可在稍后阶段移动到EPC。

The following principles shall apply for the provisioning of PDRs in the UP function:

以下原则适用于在UP功能中提供PDR：

- The CP function shall not provision more than one PDR with the same match fields in the PDI (i.e. with the same set of match fields and with the same value). The CP function may provision PDRs with the same value for a subset of the match fields of the PDI but not all;

-CP功能不应该提供多个具有相同匹配字段的PDI的PDR。CP功能可提供多个带有相同PDI匹配字段子集的PDR；

- different PDRs of a same PFCP session may overlap, e.g. the CP function may provision two PDRs which differ by having one match field set to a specific value in one PDR and the same match field not included in the other PDR (thus matching any possible value);

-同一PFCP会话的不同PDR可以重叠，例如CP功能可以提供两个PDR，这两个PDR的不同之处在于在一个PDR中将一个匹配字段设置为特定值，而在另一PDR中不包括相同的匹配字段；

- different PDRs of different PFCP sessions, not including the Packet Replication and Detection Carry-On Information IE, shall not overlap, i.e. there shall be at least one PDR in each PFCP session which differs by at least one different (and not wildcarded) match field in their PDI, such that any incoming user plane packet may only match PDRs of a single PFCP session;

-不同PFCP会话的不同PDR（不包括Packet Replication和Detection Carry-On Information IE）不应重叠，即每个PFCP会话中应至少有一个PDR，其PDI中至少有一个不同的匹配字段，使得任何进入的用户平面分组只能匹配单个PFCP会话的PDR；

NOTE 3: It is allowed for instance to provision in a PGW-U a same uplink PDR, matching any uplink traffic towards a particular application server's IP address, in two different PFCP sessions of two different UEs, as long as each PFCP session is also provisioned with another uplink PDR set with the respective UE IP address and/or uplink F-TEIDu, which allows the PGW-U to identify the PFCP session to which the packet corresponds.

注3：例如，允许在PGW-U中提供相同的上行链路PDR，以在两个不同UE的两个不同PFCP会话中匹配朝向特定应用服务器的IP地址的任何上行链路流量，只要每个PFCP会话也是配备有设置有相应UE IP地址和/或上行链路F-TEIDu的另一个上行链路PDR，这允许PGW-U标识该数据包所对应的PFCP会话。

- As an exception to the previous principle, the CP function may provision a PDR with all match fields wildcarded (i.e. all match fields omitted in the PDI) in a separate PFCP session, to control how the UP function shall process packets unmatched by any PDRs of any other PFCP session. The CP function may provision the UP function to send these packets to the CP function or to drop them. The UP function shall grant the lowest precedence to this PDR.

-作为上述原则的例外，CP功能可以提供在单独PFCP会话中通配符为所有匹配字段的PDR，以控制UP功能如何处理任何其他PFCP会话的任何PDR不匹配的分组。CP功能可提供UP功能以将这些分组发送到CP功能或丢弃它们。UP功能应授予此PDR最低优先级。

- different PDRs of different PFCP sessions, including the Packet Replication and Detection Carry-On Information IE, may overlap. The Detection Carry-On Indication indicates that the UP function shall proceed with the look-up of other PDRs of other PFCP sessions matching the packet. This is used for broadcast traffic forwarding in 5G VN Group Communication.

-不同PFCP会话的不同PDR，包括Packet Replication和Detection Carry-On Information IE，可能重叠。Detection Carry-On Indication指示UP功能应继续look-up与该分组匹配的其他PFCP会话的其他PDR。这用于5G VN Group Communication中的广播流量转发。

- different downlink PDRs of different PFCP sessions, with a PDI including the IP multicast IP address IE, may overlap. The UP function shall proceed with the look-up of other PDRs of other PFCP sessions matching the packet. This is used for downlink IP multicast traffic for IPTV service (see clause 5.25).

-具有包括IP组播IP地址IE的PDI的不同PFCP会话的不同下行链路PDR可以重叠。UP功能应继续look-up与数据包匹配的其他PFCP会话的其他PDR。这用于IPTV服务的下行链路IP多播业务。

On receipt of a user plane packet, the UP function shall perform a lookup of the provisioned PDRs and:

在接收到用户平面分组时，UP功能应执行对所提供的PDR的查找，并且：

- identify first the PFCP session to which the packet corresponds; and

-首先识别包所对应的PFCP会话；并且

- find the first PDR matching the incoming packet, among all the PDRs provisioned for this PFCP session, starting with the PDRs with the highest precedence and continuing then with PDRs in decreasing order of precedence. Only the highest precedence PDR matching the packet shall be selected, i.e. the UP function shall stop the PDRs lookup once a matching PDR is found.

-在为该PFCP会话配置的所有PDR中，查找与传入数据包匹配的第一个PDR，从具有最高优先级的PDR开始，然后按优先级降序继续PDR。只应选择与数据包匹配的最高优先级PDR，即一旦找到匹配的PDR，UP功能应停止PDR查找。

A packet matches a PDR if all the match fields which are identified with different IE type in the PDI of the PDR are matching the corresponding packet header fields unless specified otherwise. If a match field is not included in the PDI, it shall be considered as matching all possible values in the header field of the packet. If the match field is present and does not include a mask, the match field shall be considered as matching the corresponding header field of the packet if it has the same value. If the match field is present and includes a mask (e.g. IP address with a prefix mask), the match field shall be considered as matching the corresponding header field of the packet if it has the same value for the bits which are set in the mask. If a match field has multiple instances, i.e. there are several IEs with the same IE type, a packet matches this match field if any instance is matching the corresponding packet header field.

除非另有规定，否则如果在PDR的PDI中用不同IE类型标识的所有匹配字段都匹配相应的分组报头字段，则分组匹配PDR。如果PDI中不包括匹配字段，则应将其视为匹配数据包报头字段中的所有可能值。如果匹配字段存在且不包括掩码，则如果匹配字段具有相同的值，则该匹配字段应被视为与包的相应报头字段匹配。如果匹配字段存在并且包括掩码，则如果匹配字段对于在掩码中设置的位具有相同的值，则该匹配字段应被视为匹配分组的相应报头字段。如果一个匹配字段有多个实例，即有多个IE具有相同的IE类型，则如果任何实例与相应的包头字段匹配，则一个包与该匹配字段匹配。

The match fields of the PDI shall correspond to outer and/or inner packet header fields, e.g. uplink bearer binding verification in the PGW-U may be achieved by configuring a PDR with the PDI containing the local GTP-U F-TEID (for outer IP packet matching) and the SDF filters of the data flows mapped to the bearer (for inner IP packet matching).

PDI的匹配字段应对应于外部和/或内部分组报头字段，例如，PGW-U中的上行链路承载绑定验证可通过配置PDR来实现，PDI包含本地GTP-U F-TEID和映射到承载的数据流的SDF过滤器。

NOTE 4: A DL PDR can be provisioned with a UE IP address together with a Framed-Route or a Framed-IPv6-Rotue either in the PDI IE or in the Create Traffic Endpoint IE; in such case, the PDR is matched if the packet matches either the UE IP address or the Framed-Route (Framed-IPv6-Route).

注4：DL PDR可以在PDI IE或创建流量端点IE中与UE IP地址以及帧路由或帧IPv6-Rotue一起提供；在这种情况下，如果数据包与UE IP地址或帧路由（Framed-IPv6-Route）匹配，则PDR将匹配。

When one or more pre-defined PDR(s) are activated for a given PDR (see clause 5.19), an incoming packet matches the PDR if it matches one of activated pre-defined PDR(s).

当为给定的PDR激活一个或多个预定义PDR时，如果传入的数据包与激活的预定义PDR中的一个匹配，则它与PDR匹配。

The UP function should drop packets unmatched by any PDRs.

UP功能应该丢弃任何PDR不匹配的数据包。

The packet processing flow in the UP function is illustrated in Figure 5.2.1-1.

UP功能中的数据包处理流程如图5.2.1-1所示。

Figure 5.2.1-1: Packet processing flow in the UP function

图5.2.1-1：UP功能中的数据包处理流程

At the deletion of a PFCP session, the UP function shall delete the PFCP session context and all the associated non-preconfigured rules.

在删除PFCP会话时，UP功能应删除PFCP会话上下文和所有相关的non-preconfigured规则。

NOTE 5: Deleting a QER in one PFCP session does not result in deleting another QER in another PFCP session even when these two QERs have the same QER ID and/or are associated with the same QER Correlation ID.

注5：即使在这两个QER具有相同的QER ID和/或与相同的QER Correlation ID相关联的情况下，在一个PFCP会话中删除QER不会导致在另一个PFCP会话中删除另一个QER。

A UP Function controlled by multiple CP functions shall handle Rule IDs from the different CP functions independently from each other.

由多个CP功能控制的UP功能应独立处理来自不同CP功能的Rule ID。

Rule ID used for PDR, FAR, BAR, QER, URR or MAR is uniquely identifying a rule of the corresponding rule type within a session.

用于PDR、FAR、BAR、QER、URR或MAR的Rule ID唯一地标识会话中相应规则类型的规则。