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。

5.3.2 Sending of End Marker Packets 结束标记包的发送

The construction of End Marker packets may either be done in the CP function or UP function, based on network configuration, as specified in clause 5.8 of 3GPP TS 23.214 [2] for EPC and in clause 5.8.2.9 of 3GPP TS 23.501 [28] for 5GC. The support of End Marker packets by the UP function is optional.

根据网络配置，可以在CP功能或UP功能中完成End Marker分组的构造。UP功能对End Marker数据包的支持是可选的。

If the UP function indicated support of End Marker packets constructed in the UP function, the CP function shall request the UP function to construct and send End Marker packets by sending a Session Modification Request including FAR(s) with the new downstream F-TEID and with the SNDEM (Send End Marker Packets) flag set.

如果UP功能指示支持在UP功能中构造End Marker包，则CP功能应通过发送Session Modification Request来请求UP功能构造和发送End Marker包，该Session Modification Reqeust包括具有新的下游F-TEID和SNDEM标志集的FAR。

For End Marker packets constructed in the CP function, the CP function shall:

对于在CP功能中构造的End Marker包，CP函数应：

- establish (once) one standalone PFCP session not tied to any PDN connection, per the UP function, for forwarding End Marker packets, and provision the UP function to perform one GTP-U decapsulation and to forward the resulting packets without any further change towards the destination IP address of these packets;

-根据UP功能建立一个未绑定到任何PDN连接的独立PFCP会话，用于转发End Marker分组，并提供UP功能以执行一个GTP-U解封装并转发得到的分组，而不向这些分组的目的地IP地址进行任何进一步的改变；

- construct the GTP-U End Marker packets, with the destination IP address and TEID set according to the old F-TEID value, and with a source IP address set according to the UP function's F-TEID value (e.g. S1 or Iu SGW F-TEID or NG-u UPF F-TEID);

-构造GTP-U End Marker包，根据原F-TEID值设置目的IP地址和TEID，根据UP功能的F-TEID值设置源IP地址；

- encapsulate the constructed GTP-U End Marker packets in GTP-U packets according to the principles specified in clause 5.3.1 for data forwarding between the CP function and the UP function, and send them towards the F-TEID assigned in the UP function for the above PFCP session, after receipt of the PFCP Session Modification Response indicating that the UP function has switched to a new F-TEID.

-在接收到表示UP功能已经切换到新的F-TEID的PFCP Session Modification Response之后，将构造的GTP-U End Markder包封装在GTP-U包中，用于CP功能和UP功能之间的数据转发，并将它们发送到UP功能中为上述PFCP会话分配的F-TEID。

Upon receipt of a PFCP Session Modification Request modifying the F-TEID in the Outer Header Creation of a FAR, the UP function shall send the Response message only after having switched to the new F-TEID.

在接收到在FAR的Outer Header Creation中修改F-TEID的PFCP Session Modification Reqeust时，UP功能应仅在切换到新的F-TEID之后发送Response消息。