Statistical multiplexing, bandwidth allocation strategies and connection admission control in ATM networks

This paper gives a brief description and the main results of work done within the RACE 1022 project on bandwidth allocation and Connection Admission Control in ATM-based networks. Additionally, and before presenting these two main issues, some important facets of statistical multiplexing are highlighted. The key question which is answered by a bandwidth allocation algorithm is “how much bandwidth is required by a group of connections (e.g., within a VP), with certain traffic characteristics, in a certain multiplexing environment”. Answers to this question are given for specific traffic classes and mixing conditions. The advantages and the limitations of the proposed strategies are indicated. In cases where the proposed bandwidth allocation strategies fail to fulfil the specified objectives (e.g., in highly heterogeneous traffic mixes), sophisticated CAC algorithms are required. In particular, the hierarchically organised CAC strategy implemented within the RACE 1022 ATD Technology Testbed will be described in detail. This CAC scheme is based on a simple real-time processing algorithm which provides a quick acceptance decision. This decision will be refined by a precise but numerically complex background algorithm. Simulation studies confirm the potential of this concept.