Efficient Provision of Performance Guarantees in ATM Networks by means of Deterministic Traffic Handling

Intensive research efforts have by now shown that guaranteeing performance targets, such as no cell loss, bounded cell delay variation and maximum delay, requires quite strict constraints on the traffic source emission characteristics. We consider a resource allocation strategy based on the shaping of the user offered ATM traffic into a deterministic pattern. The focus of this work is the proposal of a strategy to control the cell transfer through the network, by exploiting the enforced regularity, to optimize the use of network buffering resources, thus enhancing the overall network efficiency. This is realized by a so called Cell Shuffler, located at the switch input ports. The proposed strategy aims at the following goals: i) to define an easily implementable cell transfer control mechanism, that is independent of the switching node architecture; ii) to allow a dimensioning of the node output port buffers independently of the switch load; iii) to minimize the buffer consumption due to each Virtual Circuit and eventually reap some of the potential multiplexing statistical gain, while still being able to maintain performance guarantees and fairness among different users. A preliminary performance evaluation focused on the assessment of buffer space requirements in a network node is carried out, to highlight the benefits deriving from the proposed cell transfer control strategy.