The objective is to establish a wav

The objective is to establish a wavelength path between the two MPLS LSRs (label switch routers) on the left and right hand side of the optical network [6]. At each of the numbered points, a human operator must create a lambda between the boxes and assign this lambda to the path. When we reach Point 5 we have a complete path and the LSRs can be told to bring up their connections. This kind of provisioning gives the carrier the ultimate control over its network resources, but it does require considerable configuration and monitoring, as backup paths have to be pre-configured at each stage to cope with failures. Typically, an offline routing package is used to calculate and re-optimize paths periodically, but it is always a human operator (using a NMS) who makes the actual changes.