Congestion within a communication is controlled by rate limiting packet transmissions over selected communication links within the network and modulating the rate limiting according to buffer occupancies at control nodes within the network. The differential disconnect provides for a lock out of the disconnect so as to prevent self energizing. The virtual private network tunnel parameters identify an access gateway. If these tests are successful, then the graphics acceleration is used by the software application. One embodiment further uses multiple particles to maintain multiple hypotheses with respect to localization and mapping.