Patent ID: 6292839
Filing Date: 2001-09-18
Classification: H04L

Abstract:
A method of reflexive tunneling, comprising the following steps:receiving a data packet on a second network device on a second network, from a first peer application associated with a first network device on a first network, for a second peer application associated with a third network device on the second network,wherein a first destination address in a first header in the data packet for the third network device was selected from a published list of network addresses and a first destination port in a second header in the data packet for the second peer application was selected from a published list of network ports and,wherein the selected first destination address and the selected first destination port directed the data packet to a hidden tunnel application on the second network device on the second network instead of to the second peer application associated with the third network device on the second network;selecting a communications channel on a communications link between the second network device and the third network device;modifying one or more headers in the data packet on the second network device to create a hidden virtual tunnel between the second network device and the third network device by:replacing the first destination address for the second network device in the first header with a second network destination address for the selected communications channel on the communications link between the second network device and the third network device, andreplacing the first destination port for the hidden tunnel application on the second network device in the second header with a second destination port for the second peer application on the third network device,wherein the one or more modified headers provide communication state information, and wherein the hidden virtual tunnel is hidden from the first peer application associated with the first network device and the second peer application associated with the third network device; andforwarding the data packet from the second network device to the third network device over the hidden virtual tunnel using the selected communications channel.