Transport protocols for data center networks: a survey of issues, solutions and challenges

In recent years, data centers play an important role in academia and industry for supporting various services and applications. Compared with other IP networks, data center networks have some special features such as many-to-one communication pattern with high bandwidth, low latency, auto-scaling, shallow buffered switches and multi-rooted tree topology. Owing to these special features of data center networks, traditional TCP suffers from severe performance degradation. For improving the performance of TCP in data center networks, various solutions have been proposed in recent years. This article presents a comprehensive survey of existing transport layer solutions proposed for mitigating the problems of TCP in data center networks. The objective of this article is threefold: to discuss about the issues of TCP in data center networks; to introduce various transport layer solutions and finally to compare and discuss the challenges of existing solutions proposed for improving the performance of TCP in data center networks.The authors gratefully acknowledge the anonymous reviewers for their valuable comments and suggestions for improving the manuscript. This research was supported by the Korea Science and Engineering Foundation (KOSEF) grant funded by the Korea government (MOST) (No. 2011-0023177). This research was also supported by the MSIP (Ministry of Science, ICT & Future Planning), Korea, under the "Establishing IT Research Infrastructure Projects" supervised by the NIPA (National IT Industry Promotion Agency) (I2221-14-1005)