A method for, in an accessing device of an access network, controlling an IP packet from a user equipment, UE, comprising the steps of: a. receiving an IP packet from a user equipment (S10); b. checking said IP packet and determining (S11) whether said IP packet is a multicast IP packet that is allowed to pass based on at least one of a multicast address and a type of said multicast IP packet; c. in case that said IP packet is a multicast IP packet that is allowed to pass, sending (S12) said allowed multicast IP packet in multicast form; if said IP packet is a multicast IP packet which satisfies at least one of the following conditions, taking said IP packet as an allowed multicast IP packet: - the multicast address of said multicast IP packet belongs to the predetermined valid multicast address; - said IP packet is a predetermined type of multicast IP packet; the method further comprising the following steps after step b and before step c: - when the IP packet received from the UE is said predetermined type of multicast IP packet, determining whether the times for the UE to send said predetermined type of multicast IP packet have exceeded a first predetermined value; - when the times for the UE to send the predetermined type of multicast IP packet have not exceeded the first predetermined value, taking the IP packet as the allowed multicast IP packet. a. receiving an IP packet from a user equipment (S10); b. checking said IP packet and determining (S11) whether said IP packet is a multicast IP packet that is allowed to pass based on at least one of a multicast address and a type of said multicast IP packet; c. in case that said IP packet is a multicast IP packet that is allowed to pass, sending (S12) said allowed multicast IP packet in multicast form; if said IP packet is a multicast IP packet which satisfies at least one of the following conditions, taking said IP packet as an allowed multicast IP packet: - the multicast address of said multicast IP packet belongs to the predetermined valid multicast address; - said IP packet is a predetermined type of multicast IP packet; the method further comprising the following steps after step b and before step c: - when the IP packet received from the UE is said predetermined type of multicast IP packet, determining whether the times for the UE to send said predetermined type of multicast IP packet have exceeded a first predetermined value; - when the times for the UE to send the predetermined type of multicast IP packet have not exceeded the first predetermined value, taking the IP packet as the allowed multicast IP packet. - the multicast address of said multicast IP packet belongs to the predetermined valid multicast address; - said IP packet is a predetermined type of multicast IP packet; - when the IP packet received from the UE is said predetermined type of multicast IP packet, determining whether the times for the UE to send said predetermined type of multicast IP packet have exceeded a first predetermined value; - when the times for the UE to send the predetermined type of multicast IP packet have not exceeded the first predetermined value, taking the IP packet as the allowed multicast IP packet. <EOS>