Routing and restoration in networks with hose-model traffic patterns

In a DiffServ network the service level agreements (SLAs) signed by the service provider and its customers normally specify the ingress and egress aggregate rate of each class, but provide no destination information. Traffic patterns of this kind are similar to the "hose model" which has been extensively studied in the context of VPN (virtual private network). An important issue is to determine how much traffic can be admitted to an existing network without violating the strict QoS requirement. The challenge of the problem lies in the fact even if the SLAs are given, the exact traffic matrix is still unknown because a hose-model traffic pattern only specifies the ingress and egress traffic rate constraints and there are many traffic matrixes that can satisfy the constraints. In this paper, we show how to find the optimal routing scheme that can maximize the amount of traffic admissible to a hose-model MPLS network. We also discuss how to design a hose-model restoration network. All these are important in maintaining the QoS of a SLA-based DiffServ/MPLS network.