Temporally ordered routing algorithm

In its operation the algorithm attempts to suppress, to the greatest extent possible, the generation of far-reaching control message propagation.

In order to achieve this, the TORA does not use a shortest path solution, an approach which is unusual for routing algorithms of this type.

By maintaining a set of totally ordered heights at all times, TORA achieves loop-free multipath routing, as information cannot 'flow uphill' and so cross back on itself.

The key design concepts of TORA is localization of control messages to a very small set of nodes near the occurrence of a topological change.

The protocol performs three basic functions: During the route creation and maintenance phases, nodes use a height metric to establish a directed acyclic graph (DAG) rooted at destination.

A node which requires a link to a destination because it has no downstream neighbours for it sends a QRY (query) packet and sets its (formerly unset) route-required flag.