Patent ID: 7903661

Claim:
A method of handling session packets in a first intermediary node that is configured to provide network address translation (NAT) having an inside interface coupled with a second intermediary node that is also configured to perform NAT, comprising: (a) at the first intermediary node, determining whether an end node that is coupled with an inside interface of the second intermediary node is sending keep-alive messages that cause a binding corresponding to the end node to be retained by the second intermediary node, wherein the binding associates inside and outside addresses of the end node; and (b) initiating, continuing, or inhibiting a process, for the first intermediary node to cause keep-alive messages for the end node to be sent from the end node at a frequency so as to cause the binding for the end node to be retained by the intermediary node, based on whether or how frequently the end node is currently sending its keep-alive messages.