IM-OM matching packet dispatching scheme for MSM Clos-network switches
[ 1 ] Katedra Sieci Telekomunikacyjnych i Komputerowych, Wydział Elektroniki i Telekomunikacji, Politechnika Poznańska | [ P ] employee
2007
paper
english
- Clos-network
- Dispatching Algorithm
- Packet Switching
- Packet Scheduling
EN Current packet dispatching algorithms for next generation network nodes (switches/routers), in the majority of cases, involve the request-grant-accept handshaking scheme with many iterations and the effect of desynchronization of arbitration pointers. For high-performance switches and routers the Clos switching fabric is very attractive because of its modular architecture and scalability. It is almost impossible to implement the algorithms with multiple phase iterations in the three-stage Clos-network environment with currently available technologies, as the arbitration signals need to pass through the SERDES links several times, and the delay is too long. A great many packet dispatching schemes for three-stage buffered and bufferless Clos switching fabrics were proposed in the literature. Some of them provide high throughput under uniform, others under nonuniform traffic distribution. In this paper the new packet dispatching scheme, called IM-OM Matching (IOM), is proposed and evaluated. We have eliminated the handshaking process and iterations, but it is necessary to use the central arbiter instead. IOM scheme may be implemented in MSM as well as in modified MSM Clos-network switches. We show via simulation that proposed scheme delivers very good performance in terms of throughput, cell delay and input buffers size under different traffic distribution patterns.
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