Bridges (10, 12, 14) are used to interconnect local area networks transparently. In the IEEE 802.1D standard for bridges, a spanning tree is built among the bridges for loop-free frame forwarding (FIG. 10). Although this approach is simple, it does not support all-pair shortest paths. A novel bridge...http://www.google.fr/patents/US7027453?utm_source=gb-gplus-shareBrevet US7027453 - Spanning tree alternate routing bridge protocol
