State dependent routing: Traffic dynamics and performance benefits

State Dependent Routing (SDR) is an implementable adaptive routing scheme for circuit-switched networks that is expected to improve the performance considerably over the traditional, nonadaptive schemes. SDR is distinct from most other adaptive routing schemes reported in the literature in that the routing decision for each call is based specifically on the likelihood of future call blocking as a result of the specific disposition of the arrived call. This paper conducts an extensive study to investigate the anticipated benefits of SDR in symmetric, fully connected networks. Through the numerical results obtained by an iterative fixed point algorithm, significant insight is gained in understanding the traffic patterns in the network among single- and multlink calls. Distinguishing characteristics in the traffic patterns are identified and analytical models are formulated to explain the dynamics of the network. An attempt is made to quantify the effect of incorporating in SDR additional control mechanisms such as direct preference and trunk reservation, which are well known in the literature. The paper also addresses the survivability and the scalability of the network.