Post-collaboration functional feature enhancement

The invention provides a method for enhancing IP packet forwarding function feature support after intercommunication. When a PDU session in a 5GS is transferred to a PDN connection in an EPS, the UE should identify that the functional feature is supported after an inter-system handover from the 5GS to the EPS. When a PDN connection is established in the EPS, the network indicates that the functional feature is not supported, but the network provides 5GSM parameters for ESM/5GSM interworking for the PDN connection for this purpose; and the UE should identify that the functional feature is supported after an inter-system handover from the EPS to the 5GS, and the UE should also identify that the functional feature is supported after an inter-system handover from the 5GS back to the EPS. The IP packet forwarding function features include PS data interruption and a local IP address in the TFT. 提出了一种互通后增强IP封包转发功能特征支持的方法。当5GS中的PDU会话被转移到EPS中的PDN连接时，在从5GS到EPS的系统间切换之后，UE应认定该功能特征受支持。当在EPS中建立PDN连接时，网络表明不支持该功能特征，但网络为此PDN连