1. A method of selecting a route on a network, comprising: in a converged network that includes constituent networks of various types: assigning a respective link cost to links of a plurality of routes; assigning a respective node cost to nodes of the plurality of routes; and calculating, for each route of the plurality of routes, a respective route cost based on the link cost of respective links included in the route and the node cost of respective nodes included in the route, wherein at least some of the routes span constituent networks of different types and wherein calculating the route costs includes calculating the costs for the routes that span the constituent networks of different types, wherein calculating the route costs includes calculating the cost of a route that includes a time division multiplexed (TDM) signaling link and an Internet protocol (IP) signaling link, wherein 
 route cost=Σ(link cost)+Σ(node cost) and wherein a link comprises a communications interconnection between nodes, a node comprises a hardware device for providing telecommunications switching services and/or media conversion services, the link cost includes a metric accounting for link characteristics, and the node cost includes a metric accounting for processing performed by a node associated with service-impacting factors.