Server virtualization enables dynamic workload management for data centers. However, especially live migrations of virtual machines (VM) induce significant overheads on physical hosts and the shared network infrastructure possibly leading to host overloads and SLA violations of co-hosted applications. While some recent work addresses the impact of live migrations on CPUs of physical hosts, little attention has been given to the control and optimization of migration algorithms and migration-related network bandwidth consumption. In this paper we introduce network topology aware scheduling models for VM live migrations. We propose a scheme for classifying VMs based on their workload characteristics and propose adequate resource and migration scheduling models for each class, taking network bandwidth requirements of migrations and network topologies into account. We also underline the necessity for additional migration control parameters for efficient migration scheduling.