Performance isolation is a serious issue in multi-tenant data center because interference among tenants can cause immense service troubles. Therefore, present data center provides performance isolation among tenants. However, it is limited to system resources, not network resources, nevertheless oversubscription that is caused by network interference entails troubles. Therefore, we place virtual machines (VMs) with matching algorithm into servers based on measured traffic distribution of VMs. We present our approach named Incubating that reduces oversubscription, also increases link utilization. We also show that our work has better practicality compared with prior work because we consider traffic distribution as a time unit.