Abstract—While Software Defined Networking (SDN) has
received a considerable amount of attention, improving the
scalability of an SDN controller has always been a major
concern. One of the main reasons why the controller suffers
from this scalability problem is that it is fairly often
overwhelmed by a large number of flow setup requests from the
SDN switches to the controller. These requests cause decrease in
the number of switches that the controller can deal with. Since
these requests are usually generated when flows arrive at the
switch and their corresponding entries do not exist in the flow
table due to eviction, minimizing the number of evictions also
reduces the number of requests to the controller. This paper
addresses the scalability problem and proposes the algorithm
improving the scalability of the SDN controller by dynamically
controlling the timeout value of each flow without modifying the
switches. In the proposed approach, the controller collects
various traffic parameters from the switches and predicts the
inter-arrival times of packets in a flow. Based on the
information, it dynamically adjusts the timeout value of each
flow to reserve spaces in the flow table for newly arrived flows
in advance. As a result, this avoids the evictions and reduces the
number of flow setup requests to the controller. The
benchmarking results show that the proposed algorithm
reduces the number of packets to the controller by 9.9 %.
Index Terms—Flow table, open flow, SDN, SDN controller,
timeout control.
T. Kim, K. Lee, J. Lee, S. Park are with the Department of Computer
Science and Engineering, Sogang University, Seoul, Korea (e-mail:
maxine.kth@gmail.com, kwonyong82@gmail.com,
leejunhee23@gmail.com, parksy@sogang.ac.kr).
Y.-H. Kim is with Next Communication Research Lab., Electronics and
Telecommunications Research Institute, Daejeon, Korea (e-mail:
yhwkim@etri.re.kr).
B. Lee is with SDN Research Section, Electronics and
Telecommunications Research Institute, Daejeon, Korea (e-mail:
bjlee@etri.re.kr)
[PDF]
Cite: Taekhee Kim, Kwonyong Lee, Junhee Lee, Sungyong Park, Young-Hwa Kim, and Byungjoon Lee, "A Dynamic Timeout Control Algorithm in Software
Defined Networks," International Journal of Future Computer and Communication vol. 3, no. 5, pp. 331-336, 2014.
