Analysis of adaptive routing schemes in multirate loss networks

As technology evolves, it is now feasible to implement sophisticated adaptive routing scheme on networks which support different kind of services with heterogeneous bandwidth characteristics. Adaptive routing can increase the network throughput by routing calls to less congested paths. It can also be used to bypass transmission facility failures. In this paper, we analyze and compare two adaptive routing schemes. The first is called the maximum mean time to blocking (MTB) routing which is based on the mean time to blocking measure of a link. This measure captures the traffic rates, bandwidth characteristic and link capacity information and reflects more accurately the congestion status of different paths. The second is the M² routing, which is a modification of the least loaded routing (LLR). Aggregation of link status information can significantly reduce signalling traffic. We show in this paper that with properly designed aggregation, the aggregated M² and MTB routings can have performance that approach that of the non-aggregated schemes. The use of complete sharing and restricted access policies together with trunk reservation control in multirate loss networks are also studied