Cooperated Traffic Shaping With Traffic Estimation and Path Reallocation to Mitigate Microbursts in IoT Backhaul Network

An aggregating switch (SW) network offers cost-effective accommodation to Internet-of-Things (IoT) traffic by aggregating the traffic. In such a network, it is crucial to eliminate the discarded traffic caused by the simultaneous transmission of massive IoT devices, namely microburst. Traffic shaping is a technique of storing traffic in one SW to mitigate microbursts. Conventional traffic shaping is limited because only one SW performs shaping with a limited queue length. Thus, we propose cooperated traffic shaping using multiple SWs to accommodate more traffic. We formulated equations to derive the minimum queue length with shaping rates which gradually decrease in geometric progression. To acquire the queue length using general SWs without short-cycle monitoring, we propose a scheme for estimating the instantaneous input rate and data size of microburst traffic required for our equations. If the calculated queue length cannot be prepared in the current path, we propose reallocating the path to another one with more SWs. We experimentally demonstrated the proposed coordinated traffic shaping technique by implementing it in commercial SWs with 125 emulated IoT devices. The results showed that the difference between the experimental and numerical results was below 4.2%, and the queue length can be reduced by 40% when there are three SWs. In addition, a path with two SWs was successfully reallocated to one with three SWs.