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。

5.7.2 Lawful Interception in EPC EPC中的合法监听

Requirements for support of Lawful Interception with a split SGW or PGW are specified in clauses 12.9 and 20.4 of 3GPP TS 33.107 [20].

3GPP TS 33.107 [20]的第12.9和20.4条规定了使用分离SGW或PGW支持合法监听的要求。

User plane packets shall be forwarded from the UP function to the SX3LIF (or LMISF for S8HR) by encapsulating the user plane packets using GTP-U encapsulation (see 3GPP TS 29.281 [3]).

应通过使用GTP-U封装来封装用户平面数据包，将用户平面数据包从UP功能转发到SX3LIF。

The CP function shall instruct the UP function to duplicate the packets to be intercepted and to forward them to the SX3LIF (or to the LMISF for S8HR) as specified in clause 5.2.3.

CP功能应指示UP功能复制要监听的数据包，并将其转发给SX3LIF。

For forwarding data from the UP function to the SX3LIF (or LMISF for S8HR), the CP function shall set the DUPL flag in the Apply Action and set the Duplicating Parameters in the FAR, associated to the PDRs of the traffic to be intercepted, with the Destination Interface "LI Function" and set to perform GTP-U encapsulation and to forward the packets to a GTP-u F-TEID uniquely assigned in the SX3LIF (or LMISF for S8HR) for the traffic to be intercepted. The SX3LIF (or LMISF for S8HR) shall then identify the intercepted traffic by the F-TEID in the header of the encapsulating GTP-U packet.

为了将数据从UP功能转发到SX3LIF，CP功能应在Apply Action中设置DUPL标志，并在FAR中设置与要监听的流量的PDR相关联的Duplicating Parameter，Destination Interface “LI Function”，并设置为执行GTP-U封装并将包转发到SX3LIF中唯一分配的GTP-u F-TEID，以监听流量。然后，SX3LIF应在封装GTP-U包的报头中识别F-TEID监听的流量。