The second information may also be called indication information for caching (storing) the data packet (for example, the indication information for caching the uplink data packet). The function of the indication information is to indicate whether the first node needs to cache (store) the uplink data packet, for example, indicating it is necessary to cache (store) the uplink data packet or it is not necessary to cache (store) the uplink data packet.
The third information may also be called information about the address, which indicates information about the address for transmitting the user data.
The fourth information may also be called Data Delivery Status (DDS) information. The function of the information is to indicate information related to the status of the data packet transmitted (receiving and/or transmitting) by the second node. In an embodiment, if the above fourth information is for uplink data packets, the fourth information is information about the uplink data packet delivery status, such as UL DDS. In another embodiment, if the above fourth information is for the downlink data packet, the above fourth information is the information about the downlink data packet delivery status, such as DL DDS.