This application discloses a communication method and a related apparatus. The communication method includes: A first core network element receives a first message from a second core network element, where the first message includes identification information of a first terminal and first identification information of a session, and the session indicated by the first identification information is used by a second terminal to transmit data for the first terminal; the first core network element obtains, based on the identification information of the first terminal, terminal context information corresponding to the session; and the first core network element sends a second message to the second core network element, where the second message includes the terminal context information corresponding to the session. This can directly control session permission of a terminal device, thereby improving accuracy of performing permission control on the terminal device.