Control architecture of multiple-hop connections in IP over WDM networks

In the existing functional definition of the optical network, the optical network primarily offers high bandwidth connectivity in the form of optical layer connections, where a connection is defined to be a fixed bandwidth circuit between two user network elements (also called clients). We propose to add IP routers packet processing function into the data plane of optical core networks, in order that transport service providers can provide multiple-hop connections between ISPs in addition to single-hop-only point-to-point lightpaths. Their benefits include optimized utilization of the bandwidth of lightpaths, more means to add and drop IP traffic, and flexibility of traffic engineering operations. We extend the functional models for IP-optical network interaction in the context of multiple-hop-enabled IP over WDM networks. The unified control and management supported by generalized MPLS is one of the underpinnings of the evolution from single-hop-only optical networks to multiple-hop-enabled IP over WDM networks. In order to support multiple-hop connections, we propose that the requests of connection establishment in the UNI should be extended to include the bandwidth and IP layer QoS requirements. Finally, the enhanced traffic engineering for transport service providers is discussed.