A First Look at Public-Cloud Inter-Datacenter Network Performance

Public-cloud providers do not disclose quantitative information about the performance of their inter- datacenter networks in spite of their importance and of the growing interest they are attracting. In this paper we propose an analysis of the inter-datacenter network of the two leading providers-Amazon Web Services and Microsoft Azure- only leveraging active monitoring approaches and thus not relying on information restricted to providers. Our results show that Azure inter- datacenter infrastructure performs better than Amazon's in terms of throughput (+52%, on average). On the other hand, the performance of the two providers is comparable in terms of latency, with the exception of isolated cases. Counterintuitively, lower performance may be even related to higher costs for the customer. Network management policies that may severely impact both the performance perceived by the customers and the results of the measurement activities have been observed and characterized. Finally, a comparison with previous works shows that TCP throughput has not improved recently.