MESSAGE TRANSMISSION METHOD AND DEVICE, AND COMPUTER STORAGE MEDIUM

This application discloses a packet transmission method and apparatus, and a computer storage medium, and belongs to the field of communications technologies. A first device obtains service type information of an original packet. The first device generates an ESP packet of the original packet based on a target security association, where the ESP packet includes a packet header, an ESP header, a service type field, a first encrypted part, and an ESP authentication data field, and the service type field includes the service type information. The first device sends the ESP packet to a second device. The second device parses the service type field to obtain the service type information of the original packet. The second device performs a target operation on the ESP packet based on a service policy and the service type information of the original packet. The second device may obtain the service type information of the original packet by parsing the service type field of the ESP packet, without decrypting the first encrypted part, thereby reducing calculation overheads in a process in which the second device determines a service type of the original packet.