NATALIE: An Adaptive, Network-Aware Traffic Equalizer

The bandwidth of multiple physical communication links can be aggregated with inverse multiplexing to create a single, higher capacity logical communication link. However, achieving the maximum possible aggregated bandwidth becomes challenging as the communication characteristics of the underlying links (e.g., available bandwidth, packet loss rate) change with time. In this paper we introduce NATALIE, a Network-aware traffic equalizer. NATALIE combines an arbitrary set of network interfaces and schedules IP packet transmissions over those interfaces in a weighted round-robin fashion. To achieve the maximum possible throughput, NATALIE measures the communication characteristics of the underlying links and dynamically adjusts its scheduler to assign packets to each link in proportion to its available capacity. We describe NATALIE´S implementation, the test environment we built on the Emulab Network Testbed, and the results of experiments demonstrating NATALIE´S throughput performance for TCP connections over diverse underlying links with cross-traffic.