# JSSTR: A Joint Server Selection and Traffic Routing Algorithm for the Software-Defined Data Center
## 3 Related Work
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**No.** & **Authors** & **Technique** & **Research Focus/Contibution/Features** \\ \hline
1 & [PERSON] et al. [11] & Controller-based server response time measurement; Dynamic server selection & The controller periodically sends packet-out messages to measure server response time. There is no need to add extra devices to measure server response time. The server with the minimum response time or minimum standard deviation in \(m\) historical data of response time will be chosen as the destination server based on the difference value between maximum and minimum server response time. & The CPU occupancy rate, memory occupancy rate and response time are collected and recorded as the server load. The weight and selection probability of all servers will be calculated as the servers’ load change. The system selects a server as the destination server based on the calculated selection probability. & The F-test method is executed to analyze the data traffic of each port. The selection probability of each port is calculated. The traffic is dynamically reflected based on the selection probability. \\ \hline
4 & [PERSON] et al. [18] & Evaluating the SDN load balancers; round-robin; random- CPU usage & A comprehensive methodology for evaluating the SDN load balancers is proposed. The performance of the round-robin-, random- and CPU usage-based server load balancing strategies is evaluated. The active and reactive load balancers are evaluated in the SDN scenario. \\ \hline
5 & [PERSON] et al. [10] & Round-robin-based load balancing method; Random-based load balancing method & The round-robin- and random-based server load balancing method & The round-robin-based server load balancing method and least-comnections-based server load balancing method are implemented and compared in SDN. It is found that the least-connections-based server load balancing method performs better than the round-robin-based server load balancing method. \\ \hline
6 & [PERSON] et al. [20] & Round-robin-based server load balancing method; Least-comnections-based server load balancing method & The round-robin-based server load balancing method and least-comnections-based server load balancing method are implemented and compared for SDN. It is found that the least-comnections-based server load balancing method performs better than the round-robin-based server load balancing method. \\ \hline
7 & [PERSON] et al. [24] & Dynamic server load balancing; Priority-based server selection; Polling method & The proposed dynamic server load balancing method periodically obtains each server’s load and computes its priority value. The first half of servers will be listed in order of decreasing priority values. A poling method is used to dispatch requests to these servers. & The proposed dynamic server load balancing method is designed to estimate the resource utilization and average response time of the web server. The utility function, RBF neural networks and adaptive neuron-fuzzy inference system are proposed to adjust the predicted values of the queuing model. \\ \hline
9 & [PERSON] et al. [27] & Bellman-Ford algorithm; Self-defined criticality and decision index of link & It computes and uses the first \(k\) shortest paths between every possible pair to calculate the defined criticality of each link. The amount of traffic flows and remaining bandwidth of each link are utilized to find the congestion index. The Bellman-Ford algorithm is executed to calculate the routing path between the source and destination. \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Main differences between the proposed method and the exiting methods. BCMP, [PERSON], [PERSON], [PERSON] and [PERSON].