The effect of management structure on the performance of interconnected packet-switched networks

A multi-layer model is used to study the effect of management structure on the performance of connection-oriented packet-switched networks managed via fixed threshold call admission policies. Call admission decisions are based on estimates of the number and characteristics of currently held calls, which may be inaccurate due to uncertainties in the measurement process or to the use of untimely information. Let the state estimate be represented as the true state value offset by a noise factor. The standard deviation of the estimation error serves as a key parameter in representing the complexity, coverage, extensiveness, and cost of the implemented network management and information collection procedure. For a single-domain network the effects of Gaussian noise on blocking, throughput, and the probability of excess calls are examined and used to define a measure of performance, the throughput capacity trajectory, which gives maximum throughput levels for fixed packet blocking, packet delay, and probability of excess call constraints. In a multi-domain network a particular network manager/controller may have complete information about its own domain, but limited, aggregated, or untimely information about other domains. Tradeoffs between centralized and distributed decision-making are discussed and a mechanism is provided for comparing various management structures as well as determining good values for admission control thresholds.