FDB: a high-performance fault-tolerant switching fabric for ATM switching systems

The authors propose a unified scheme to enhance both the fault-tolerance and the performance of the delta network for asynchronous-transfer-mode (ATM) switching systems. In this scheme, the number of the input/output links in each switching element (SE) is doubled, compared to that used in the delta network, to widen the path between two stages. Buffer modules are also added to the SEs to serve as a reservoir to store the conflicting packets which would be lost otherwise. With the link placement algorithm introduced, the resulting fault-tolerant double-link buffered (FDB) network not only preserves the self-routing property of the delta network, but also is 1-fault tolerant. Since packets will not be lost within the network and the routing path is uniquely set, regardless of the existence of a faulty SE/link, the order of the packets is preserved. The addition of the buffer modules and links is shown to be an effective way to increase the throughput of the network. The FDB network is highly modular, with high performance. In addition, the order of packets is preserved