Abstract: Some embodiments provide a method that identifies multiple paths between a first site and a second site. A security association (SA) is established for transmitting encrypted payload from the first site to the second site in a virtual private network (VPN) session. The method selects a path based on metrics that are obtained for the paths. The selected path is defined by a first endpoint address of the first site and a second endpoint address of the second site. The method sends a message from the first site to the second site to update the SA to switch from using an original path to using the selected path. The message indicates the first and second endpoint addresses. The method transmits a packet including a payload that is encrypted according to the updated SA.

Abstract: Some embodiments provide a method that collects metrics for one or more paths of a first tunnel implementing a first security association (SA) and for one or more paths of a second tunnel implementing a second SA. The method selects a path based on the collected metrics of the paths of the first and second tunnels. When the selected path belongs to the first tunnel, the method encrypts data transmitted as encrypted payload of the first SA and transmits the encrypted payload in the first tunnel. When the selected path belongs to the second tunnel, the method encrypts data to be transmitted as encrypted payload of the second SA and transmits the encrypted payload in the second tunnel.

Abstract: A method for increasing the surface area and roughness of metals, ceramics and composites on a micro-scale, and the surfaces themselves, is disclosed whereby a laser beam having a radiation wavelength of from UV to infrared is pulsed onto the surface of the material. The energy density of the radiation is between 0.01 to 15 J/cm.sup.2 and at least 50 pulses of radiation having duration of from 1 picosecond to 1 millisecond are used on each area. The surface structures formed are semi-periodic and are from 1/4 to several hundred microns in magnitude.

Abstract: A method for increasing the surface area and roughness of metals, ceramics and composites on a micro-scale, and the surfaces themselves, is disclosed whereby a laser beam having a radiation wavelength of from UV to infrared is pulsed onto the surface of the material. The energy density of the radiation is between 0.01 to 15 J/cm.sup.2 and at least 50 pulses of radiation having duration of from 1 picosecond to 1 millisecond are used on each area. The surface structures formed are semi-periodic and are from 1/4 to several hundred microns in magnitude.