The disclosure includes a method for establishing a connection with QoS assurance. In the method, a router receives a first IPv6 packet for establishing a first connection, wherein the first IPv6 packet includes a first QoS requirement for the first connection in a hop-by-hop extension header of the first IPv6 packet. Then, the router modifies the first IPv6 packet by setting first information in the hop-by-hop extension header of the first IPv6 packet, where the first information indicates that the router meets the first QoS requirement. Furthermore, the router sends the modified first IPv6 packet to a second router based on a destination IP address of the modified first IPv6 packet.