Routing and flow control on the MetaNet: an overview

We review the underlying principles and design of the MetaNet, a LAN/MAN architecture with an "arbitrary topology" (i.e., a switch-based LAN). Its design provides on one hand a service in which every node can try to transmit asynchronously, in a bursty manner without reservation (as much as it can) as in shared-media LANs. On the other hand, the network access and flow control ensure the following properties: (1) no cell/packet loss due to congestion, (2) fair access to the network, (3) no deadlocks, (4) dynamic self-routing, and (5) broadcast-with-feedback. The switching over this network requires only a single buffer per link-as in buffer insertion rings. The dynamic self-routing on the MetaNet is a variant of deflection routing. It makes on-line routing decisions based on the local flow of traffic (load conditions). Unlike other deflection techniques the MetaNet routing is along a global sense of direction, which guarantees that packets will reach their destinations. Thus, we call this method convergence routing (previous deflection algorithms do not guarantee deterministic routing convergence, i.e., a cell/packet can be deflected indefinitely inside the network). A natural implementation of a global sense of direction is embedding a virtual ring in a tree that spans the network. The links of the virtual ring are numbered sequentially, such that the numbering establishes a linear measure of the distance to the destination. © 1994.