A new distributed route selection approach for channel establishment in real-time networks

In this paper, we propose a new distributed route selection approach, calle d parallel probing, for real-time channel establishment in a point-to-point network. The existing distributed routing algorithms fall into two major c ategories: preferred neighbor based or flooding bared. The preferred-neighb or approach offers a better call acceptance rate, whereas the flooding appr oach is better in terms of call setup time and routing distance. The propos ed approach attempts to combine the benefits of both preferred neighbor and flooding approaches in a way to improve all the three performance metrics simultaneously, This is achieved by probing k different paths in parallel, for a channel, by employing different heuristics on each path. Also, the pr oposed approach uses a notion called intermediate destinations (ID's), whic h are subset of nodes along the least-cost path between source and destinat ion of a call, in order to reduce the excessive resource reservations while probing for a channel by releasing unused resources between ID's and initi ating parallel probes at every ID. Further, it has the flexibility of adapt ing to different load conditions by its nature of using different heuristic s in parallel, and hence, a path found for a channel would have different s egments (a segment is a path between two successive ID's), and each of thes e segments would very well be selected by different heuristics, The effecti veness of the proposed approach has been studied through simulation for wel l-known network topologies for a wide range of quality-of-service and traff ic parameters, The simulation results reveal that the average call acceptan ce rate offered by the proposed route-selection approach is better than tha t of both the flooding and preferred neighbor approaches, and the average c all setup time and routing distance offered by it are very close to that of the flooding approach.