An analytic comparison of shortcut switching strategy and spanning tree protocol

Ethernet-based networking technology is popular choice for local area networks. One weakness of existing Ethernet architecture is its use of spanning tree protocol (STP) that provides a loop-free forwarding topology in Ethernet networks. In STP, all customers need to use the same spanning tree and there is not any traffic engineering mechanism for load balancing. This results in uneven load distribution and bottlenecks especially close to the Root. In traditional STP, there are some blocked links, with no traffic on them to prevent loop in switching. As a solution, recently we proposed using shortcut switching strategy (SSS) instead of STP. In this paper, we analytically show that using SSS instead of STP improves the efficiency by decreasing the routing cost. Therefore using SSS decreases the average traffic volume on links and improves load balancing.