Impact of SDN on optical router bypass

Internet traffic is growing rapidly, driven by new applications such as the Internet of things (IoT). To overcome router scaling limitations, router bypass has been introduced. Traditional bypass is based on provisioning fixed-size bypass channels, which was shown to underutilize link capacity. In software defined networking (SDN), router bypass can be requested as a service by the application layer. This study explores the opportunity to bypass routers efficiently without the link underutilization of the traditional bypass.We combine SDN and dynamic layer provisioning to implement dynamic router bypassing and show how this leads to improved efficiency. A simulation built to compare the traditional bypass with the SDN-based bypass showed that SDN-based bypassing enhanced efficiency by 33%. When bypass traffic is increased, we show that the output capacity of a node increases up to 56%, limited by optical capacity rather than router capacity.