Patent ID: 8688077

Claim:
A communication system for providing a mobile telecommunication service, comprising: a communication network configured to transmit messages based upon an Internet protocol; a mobile computer; an access network for the mobile computer in which messages are transferred using a multicast process; a network connection computer that connects the access network to the communication network; a plurality of access points in the access network, each access point having at least one respective access point connection computer configured to establish a communication connection with the mobile computer; and an authentication verification computer for establishing and managing trusted relationships between a plurality of communication elements; wherein the network connection computer and the access point connection computer are each configured to execute a packet filtering method for security-related protection of the communication system when receiving and transmitting messages; the packet filtering method executed by the access point connection computers comprising: determining a source address of a message, and rejecting the message if that message has at least one access point connection rejection characteristic, the at least one access point connection rejection characteristic being at least one of a source address identifying a non-mobile communication element that originates from a wireless link, message information that indicates the message arrives at an upstream interface and originates from a wireless link, and the message is an advertisement message from an access point that arrives at an input-side interface and originates from a wireless link; the packet filtering method executed by the network connection computer comprising: determining a source address of a message, and rejecting the message if that message has at least one network connection rejection characteristic, the at least one network connection rejection characteristic being at least one of the source address of the message indicates the message is from a mobile computer, the source address of the message indicates that the message is from the access network, the source address of the message indicates the message is a MOMBASA-internal message, the message conforms to the Internet Group Management Protocol, and the message conforms to the Independent Multicast-Sparse Mode protocol; and wherein the network connection computer and the authentication verification computer are configured to execute an overload control method by providing a communication protocol for the communication elements in order to prevent a malfunction of the communication elements as a result of an attack.