Cisco Systems Juniper Networks This document describes use cases for gathering routing, forwarding and policy information, (hereafter referred to as topology information), about the network. It describes several applications that need to view the topology of the underlying physical or logical network. This document further demonstrates a need for a "Topology Manager" and related functions that collects topology data from network elements and other data sources, coalesces the collected data into a coherent view of the overall network topology, and normalizes the network topology view for use by clients -- namely, applications that consume topology information.