Patent ID: 7181612

Claim:
A method for facilitating Internet security protocol (IPsec) based communications through a device that employs address translation in a telecommunications network, the method comprising the steps of: receiving a first electronic message from a first node, wherein: the first node is associated with a first network address; the first electronic message is based on IPsec; the first electronic message is associated with a first identifier; the first identifier is a first IPsec Security Parameter Index (SPI); the first identifier is generated by the first node; and the first electronic message is addressed to a second network address; the device generating a value based on the first identifier and a specified scheme, wherein the specified scheme is a computer-implemented operation that is known to both the device that employs address translation and a second node; sending the first electronic message to the second node based on the second network address, wherein the first electronic message includes a particular network address that is associated with the device instead of the first network address; receiving a second electronic message from the second node, wherein: the second electronic message is based on IPsec; the second electronic message is addressed to the particular network address; the second electronic message is associated with a second identifier that is different than the first identifier; the second identifier is a second IPsec SPI; and the second identifier is generated, based on the first identifier and the specified scheme, by the second node; the device determining whether the second electronic message is directed to the first node based on the value and the second identifier; and sending the second electronic message to the first node at the first network address when the second electronic message is determined to be directed to the first node.