Delay-Sensitive Multicast in Inter-Datacenter WAN Using Compressive Latency Monitoring

Multicast routing in inter-datacenter wide area networks is to compute a multicast tree from a source datacenter to multiple destination datacenters. Software-defined networking enables optimal delay-sensitive routing for multicast sessions in inter-datacenter WANs. Delay-sensitive routing requires the controller to obtain the up-to-date latency of every link. However, the communication overhead and time for collecting the latency information of all links can be prohibitively high for the controller to perform real-time scheduling in a WAN. Inspired by the sparsity of link load information in WANs, we propose compressive latency monitoring, a real-time method for collecting a near-accurate latency information of all links. The controller only needs to collect the latency information of a small subset of significant links and then estimates the latency information of insignificant links. We use real-world network topologies to simulate multicast routing both under the compressive latency monitoring and global latency monitoring. Simulation results show that the compressive latency monitoring can achieve nearly good network throughput performance as the global monitoring with much less communication overhead and in a more timely fashion.