aspects of the invention pertain to transmitting packet data across a computer network . the packets may be sent via one or more distinct routes from a source to a destination . each route may employ multiple routers disposed along the network . non - colliding routes are determined by transmitting pairs of probe packets along the routes . a first probe packet has a maximal length , and a second probe packet has a minimal length . depending on the order of arrival of the probe packets , the system determines whether two transport layer ports at the destination device collide . if there is a collision , then the system searches for a set of non - colliding ports . once the non - colliding ports are determined , application data may be sent as packets along the different routes to those ports .