An automated routing system configured to route a private line circuit or a wavelength circuit, said system arranged to receive a service request comprising a request to install a communication line in a communications network, wherein said communication line is said private line circuit or said wavelength circuit, the system arranged to design a route in the communications network through which said communication line can be installed between a source location and a destination location as specified in the service request for the communication line, said designing based on current available capacity between the source location and the destination location, the system comprising: a find module configured to identify one or more possible capacity links within the communication network, each capacity link representing an ability to transport data over a predefined segment of the communication network between the source location and the destination location; a build module configured to construct a capacity graph of the communication network depicting connectivity of each of the possible capacity links to an adjacent possible capacity link such that one or more possible routes are defined between a source node representing the source location and a destination node representing the destination location; and a select module configured to apply a routing algorithm to the capacity graph to select an optimal route from the one or more possible routes based on a calculated cost factor of installation of the communication line into each of the possible routes within the computer network, wherein the service request specifies intermediate locations through which the communication line must pass between the source location and the destination location, the system further comprising: a define module configured to define an intermediate node corresponding to each intermediate location such that the find module identifies only possible capacity links that may be joined between adjacent intermediate nodes, a first intermediate node and the source node and a final intermediate node and the destination node. a find module configured to identify one or more possible capacity links within the communication network, each capacity link representing an ability to transport data over a predefined segment of the communication network between the source location and the destination location; a build module configured to construct a capacity graph of the communication network depicting connectivity of each of the possible capacity links to an adjacent possible capacity link such that one or more possible routes are defined between a source node representing the source location and a destination node representing the destination location; and a select module configured to apply a routing algorithm to the capacity graph to select an optimal route from the one or more possible routes based on a calculated cost factor of installation of the communication line into each of the possible routes within the computer network, a define module configured to define an intermediate node corresponding to each intermediate location such that the find module identifies only possible capacity links that may be joined between adjacent intermediate nodes, a first intermediate node and the source node and a final intermediate node and the destination node.