保证速率的核心无状态分组调度算法

提出一种新的核心无状态分组调度算法VCSVC(G)(vector core-stateless virtual clock).该算法在边界节点为分组计算理想模型下各节点对应的虚拟延迟,组成虚拟延迟矢量带在分组头中,是核心节点排序的依据,其长度上限G利用局部平均法实现.证明了VCSVC(G)与VC(virtual clock)具有相同延迟保证能力,计算了实际算法与理想模型速率保证精度的误差上限,并与两种核心无状态代表算法进行了比较分析.结果表明,通过调节参数G,算法可达到开销与速率保证精度的理想折衷,适用于广泛的用户需求.

Rate-Guaranteed Core-Stateless Packet Scheduling Algorithm

A new core-stateless packet scheduling algorithm,VCSVC(G)(vector core-stateless virtual clock),is proposed.When a packet arrives at the edge of a network of VCSVC(G) servers,the ingress node computes the virtual delays for each packet at every node it traverses under the corresponding ideal single-flow system and encodes them into a virtual delay vector carried by the packet itself.The virtual delay vector is used for packets sorting at core nodes,and the upper bound G on its length is achieved by partial average technique.It is proved that VCSVC(G) has the same delay properties as the virtual clock(VC).The maximum difference on the accuracy of rate guarantee between a network of VCSVC(G) servers and the corresponding ideal single-flow system is calculated.The algorithm is finally compared with two well-known core-stateless algorithms.From these results,it can be concluded that the balance between packet overhead and the accuracy of rate guarantee can be achieved by setting the parameter G appropriately,meaning that VCSVC(G) can meet a wide range of QoS requirements.