“Dead reckoning”-a primitive and efficient self-routing protocol for ultrafast mesh networks

The authors describe a new approach to the problem of self-routing in ultra-high-speed multi-computer interconnection networks. The method is based on the concept of “dead reckoning” (self-navigation without the use of landmarks), and is applicable to networks with a mainly regular mesh topology. The packet header contains, in addition to the usual destination address, a tiny amount of directional information (as little as 2 bits in the case of the Manhattan street network). With this additional data, the algorithm for path selection at the network nodes becomes extraordinarily simple, allowing very fast processing with good routing efficiency and high throughput. Most significantly, with this method it is not necessary to read each binary digit of the destination address of every packet arriving at every intermediate routing node; it is sufficient only to perform a single-stage pattern match between the packet address and the address of the routing node. This feature, and the low latency of this self-routing technique, make it particularly well suited to ultrafast photonic networks