Patent ID: 8059641

Claim:
In a Virtual Private Network or VPN comprising a Network Address Translation or NAT device and a voice communication device, a method to determine an encapsulation used by a tunnel, comprising: a processor selecting a first encapsulation method for use in a pre-existing tunnel; the processor transmitting a packet encapsulated by the first encapsulation method; the processor determining if the packet has been received; the processor determining if a response to the packet has been received; if either the packet or the response has been received, the processor increasing a receive packet counter; the processor waiting for a selected period of time; the processor determining if the receive packet counter has been increased; if the receive packet counter has not been increased in the selected period of time, the processor selecting a second encapsulation method; and the processor repeating the transmitting through selecting steps (b) and (c) using the second encapsulation method.