Shortcut Switching Strategy in Metro Ethernet Networks
IEEE Spanning Tree Protocol (STP) is a layer-2 protocol which provides a loop-free connectivity across various network nodes. STP does this task by reducing the topology of a switched network to a tree topology where redundant ports are blocked. Blocked ports are then kept in a standby mode of operation until a network failure occurs. In STP, there is not any traffic engineering mechanism for load balancing. This results in uneven load distribution and bottlenecks especially close to the Root. This protocol imposes a severe penalty on the performance and scalability of Metro Ethernet networks, since it makes inefficient use of links and switches.