Robust Optimization for Congestion-Aware Scheduling Model for Virtualized Network Update

As network services continue to diversify and scale, operators increasingly rely on Virtual Networks (VNs) to flexibly deploy and manage differentiated services over shared physical infrastructure. To accommodate evolving traffic patterns and resource demands, VN configurations are frequently updated through migration. A central challenge is to ensure service continuity while minimizing bandwidth overhead and avoiding network congestion during the migration process.This paper presents a congestion-free VN migration scheduling model that jointly minimizes the number of migration rounds and bandwidth reservations. The proposed method constructs a round-aware dependency graph to capture congestion-related constraints and uses a greedy algorithm to iteratively select feasible migration sets and adjust bandwidth allocation. Experimental results show that the proposed strategy reduces migration rounds by up to 32% and improves bandwidth efficiency while effectively alleviating network congestion, demonstrating its practicality in dynamic network environments.