To satisfy the increasing bandwidth requirement of Fibre Channel (FC) switched networks

Virtual Channel (VC) architecture was proposed in new version FC protocols

in order to allocate traffic flows by logical communications channels.Under hard real-time constraint

VC has been expanded from "point-to-point" to "end-to-end"

and this paper proposes the allocation scheme of VC based on Network Calculus and token bucket to reduce the end-to-end delay of traffic flows in whole FC networks.Thus it has been solved the three hard works in FC protocols:how to determine the number of each kind of VC;how to guarantee each VC's credit;and how to choose the path of each VC.Computer simulations results show that VC allocation scheme has good flexibility with traffic increasing intensity

thus enhance the availability of VC architecture into FC switched networks.