TopGen: A Library to Provide Simulation Tools with the Modeling of Interconnection Network Topologies

Topology modeling is a challenging topic in the design and development of tools that simulate the behavior of interconnection networks. During the last years we have seen the birth of several simulation tools and frameworks modeling interconnects, some of them doing brilliant efforts to do the code re-usable and extensible. The main differences among these simulation tools and frameworks is the level of granularity and abstraction of their network models. Different network models may generate duplicated efforts in modeling certain aspects of them, such as the network topology or the routing algorithm. If the topology generation and routing algorithm modeling were separated from the modeling of other network aspects, then the simulator developers could focus on developing non-existing models and new functionality, without wasting time in doing a work previously done by other simulation tool developers. In this paper we describe TopGen, an external library that can be integrated with any tool that simulates interconnection networks. TopGen provides a compendious of well-known network topologies that can be used to interconnect the network components, such as end nodes, channels, switches and routers. It also provides the corresponding knowledge to apply a compendious of routing algorithms to the modeled network topologies. TopGen also supports the definition of customized topologies that are not the standard ones, thanks to a special interface used for this purpose. We also provide details on how to integrate TopGen with a network simulator, by means of a simple API. Finally, we describe several use cases of the TopGen library.