Migrating to an Ethernet-centric Infrastructure

Regular Ethernet (i.e. IEEE 802.1D) found in local area networks is connectionless, basically meaning that packets can take an arbitrary path to get from point A to B and each packet is treated independently. In determining that path it uses techniques such as spanning tree protocol and broadcast of unknown packets which can have unpredictable consequences in terms of latency, congestion and restoration time. Connection-oriented Ethernet establishes an explicit end-to-end path for all related packets between point A and B. The connection is an entity which can have parameters such as bandwidth on which traffic engineering can be performed. For example, an algorithm can determine whether or not to admit a new connection based on the capacity available along the path. Performance monitoring can be applied to asses the health of the connection to determine whether it needs to be switched to a backup path. These functions - only possible with a connection - enable Ethernet to be as deterministic, reliable and manageable as TDM circuits, but with better economics and flexibility.