Patent ID: 8090845

Claim:
A method for traversing a firewall device to maintain a registration between a first device and a second device separated by the firewall device, the method comprising: intercepting a registration message from the first device to the second device: determining, after intercepting the registration message, whether it is time to renew the first device's registration by determining whether another registration message from the first device will be intercepted prior to an expiration of a first timeout period defined by the second device; forwarding the registration message to the second device if it is time to renew the first device's registration; sending a substitute response to the first device without forwarding the registration message to the second device if it is not time to renew the first device's registration, wherein the substitute response includes the second timeout period; intercepting a response message from the second device to the first device, wherein the response message includes the first timeout period; and replacing the first timeout period in the intercepted response message with a second timeout period based on a binding lifetime of the firewall device before forwarding the response message to the first device.