A two-dimensional toroidal network is simply a rectangular mesh where opposite nodes on the left and right boundaries are connected to each other and opposite nodes on the upper and lower boundaries are also connected to each other. Examples of toroidal based metropolitan area networks are HR4-NET and Manhattan Street Network (MSN). The original routing algorithm for HR4-NET proposed by Borgonovo and Cadorin, however, does not direct packets through shortest paths. This paper presents shortest path routing algorithms for HR4-NET, which are distributed and fail-safe. These algorithms can also be applied to multiple traffic types. Simple routing rules that use of the regular structure of the network are compared to MSN. © 1990.
Wong, J. S. K., & Kang, Y. (1990). Distributed and fail-safe routing algorithms in toroidal-based metropolitan area networks. Computer Networks and ISDN Systems, 18(5), 379–391. https://doi.org/10.1016/0169-7552(90)90122-9