Best nexthop Load Balancing Algorithm with Inband network telemetry

We proposed a best nexthop load-balancing algorithm that helps avoid the congestion path by using global network information, then compared the best nexthop algorithm with the ECMP algorithm. The best nexthop algorithm collects the network information in real time by using In-band network telemetry. The collected network information is hop latency, queue depth, and link utilization. Each switch stores the network information and calculates the degree of congestion as the sum of metric values for each path. When the traffic arrives, each switch divides the traffic into flowlet units and forwards each flowlet to the least-congested path. We compared the throughput of the best nexthop algorithm to that of the ECMP algorithm in three scenarios. In the first scenario, we send 10 flows sequentially and measured the throughput per the number of flows. The best nexthop algorithm shows stable throughput, but the ECMP algorithm shows significant descent throughput after the number of flows exists three. In the second scenario, we send traffic from two different sources to two destinations. The best nexthop algorithm showed 27% higher throughput than the ECMP algorithm in this scenario. In the third scenario, we send a large burst of traffic from a single source to a single destination. The best nexthop algorithm showed 81% higher throughput than the ECMP algorithm in this scenario. These results show that the best nexthop algorithm performs better than the ECMP algorithm in congested status.