Users can now connect to the Internet through a wide variety of access networks and communication terminals. This has brought a great demand for cloud computing which allows users to enjoy various Internet services provided by data centers (DC) anytime, anywhere. In cloud computing, the problem arises that a user's quality of service is unfair among users who are different distances from DCs. To provide fair communication service to each user, we previously proposed a bandwidth allocation scheme based on collectable information in DC networks and showed the effectiveness of this approach in a case where bottleneck links exist in DC networks. However, if bottleneck links exist outside of DC networks, the link utilization in DC networks will be degraded. In this study, we propose a bandwidth reallocation scheme based on collectable information to improve link utilization in DC networks. We have confirmed the effectiveness of this approach through simulation evaluations.