Core-stateless Fair Bandwidth Allocation for Guaranteed Services, Part II: Proportional Allocation of Excess Bandwidth

Maintaining scheduling parameters only in each packet´s header make it difficult for core-stateless networks to provide deterministic (zero loss) fair bandwidth allocation to each flow. Based on VCSGR, this paper presents a new algorithm, called FVCSGR (fair-VCSGR). In a network of FVCSGR, the arriving traffic of each flow is divided at the ingress node into a set of layers according to its reserved rate. Every packet is marked at an ingress node with a layer label and two virtual delay vectors: the basic vector and the fair vector. The basic vector which comes from VCSGR is used to provide accurate basic bandwidth guarantees and the same upper bound on end-to-end delay as its GR counterpart. On the other hand, the fair vector is used with layer label to guarantee proportional fair bandwidth allocation. We show that the out-of-order problem originated from layer scheduling can be restricted within a narrow range