Scheduling Model for Congestion-free Virtualized Network Update

This paper proposes a scheduling model for updating resource allocations for virtualized networks (VNs) without congestion. The proposed model determines the schedule of migrating traffic flows on VNs from old routes to new routes. The model aims to minimize the number of rounds required to complete the update of all existing VNs. We evaluate the performance of model in terms of the percentage of trials where feasible update scheduling exists and the number of rounds required to complete the update. Numerical results show that more rounds are required to achieve congestion-free update when the traffic demand or the number of VNs increases. The number of required rounds tends to remain the same when the maximum number of rounds exceeds a certain value; this observation helps network operators estimate the time required for VN update.