Patent ID: 8730929

Claim:
A NAT (Network Address Translation) binding method for maintaining a NAT binding by a computing device connected with a mobile terminal via a wireless network, an edge NAT router connected to the wireless network, and one or a plurality of other routers between the edge NAT router and the computing device, the NAT binding method comprising: sending a heartbeat packet to the edge NAT router according to a second time interval shorter than a first time interval, to maintain address mapping relationships for the mobile terminal in the edge NAT router, thereby maintaining a link between the mobile terminal and the computing device, wherein the address mapping relationships for the mobile terminal are configured to be maintained by the edge NAT router for the first time interval, and a Time To Live (TTL) set value of the heartbeat packet progressively decreases to 0 as the heartbeat packet reaches the edge NAT router, receiving a data packet from the mobile terminal according to a third time interval that is greater than the first time interval, thus the computing device reconfigures the TTL value due to broken link or change of routing, receiving a data packet from the mobile terminal prior to sending the heartbeat packet, wherein the address mapping relationships for the mobile terminal comprises information concerning a mapping of a source address of the data packet to a source address of the edge NAT router and a mapping of a destination address of the data packet to a destination address of the mobile terminal, detecting a present TTL value of the data packet when receiving the data packet; acquiring the number of the hops by subtracting the present TTL value from a standard TTL value of the data packet; configuring an initial TTL value of the heartbeat packet to an addition result of the number of the hops and an adjustment offset; and adjusting the initial TTL value of the heartbeat packet by performing a send-response communication with the mobile terminal, until acquiring a TTL value of the heartbeat packet that the mobile terminal cannot receive the heartbeat packet, thereby using the TTL value as the TTL set value, wherein the send-response communication comprises: sending, by the computing device, the heartbeat packet including the initial TTL value to the mobile terminal; sending, by the mobile terminal, a response packet back to the computing device in response to receiving the heartbeat packet; decreasing, by the computing device, the initial TTL value of the heartbeat packet by 1 after receiving the response packet; and repeating, by the computing device, the steps of sending the heartbeat packet and decreasing the initial TTL value of the heartbeat packet, until no response packet corresponding to the sent heartbeat packet is received from the mobile terminal.