Case Study QOS in the Data Center
Miguel Barreiros, Peter Lundqvist · 2016
The legacy traffic pattern for data centers has been the classical client-server path and model. The increased demands on consistent, predictable performance and latency, while at the same time being flexible enough to easily grow and scale in case of need, puts new demands on data center topology and structure. Experts and designers vary on what is the best way to implement quality of service (QoS) functions in the data center. This chapter focuses on the East-West traffic and identifies QOS scenarios where packets are either dropped or delayed causing sessions rate being severely decreased inside the data center itself. It examines what is the ultimate buffer size for networking equipment inside a data center if the majority of application and traffic is transmission control protocol (TCP) based, since congestion results in TCP backoff and smaller TCP congestion window (CWND).