Distributed QoS Routing Using Bounded Flooding

Quality-of-Service (QoS) routing is indispensable to real-time applications in integrated services packet-switching networks. However, existing QoS-routing schemes based on either request ooding or link-state dissemination are ineecient in terms of message overhead and/or operational cost. This paper proposes a QoS-routing algorithm with bounded ooding which not only dramatically reduces message overhead and operational cost, but also provides good performance. The overhead is reduced by limiting the search area only within which connection-request messages are ooded. Since our scheme is based on ooding, it does not require path calculation nor link-state dissemination, which can be very expensive. In order to limit the search area, we employ a distance table at each node which stores hop counts of the minimum-hop paths to all the nodes reachable via its outgoing links. Unlike link-state routing, the proposed scheme only needs network-topology information that changes much less frequently than link-load states. Extensive simulation results have demonstrated the eeectiveness of the proposed scheme in terms of performance, operational cost and message overhead. Especially, it is shown to be much better than all the other existing QoS-routing schemes in terms of message overhead and operational cost, while providing reasonably good performance.