Math to the Core

A breakthrough by researchers at Cornell University ended a decades-long quest, revealing the characteristic equations that define any packet-switched network. These researchers then implemented their breakthrough as HALO, the world’s first distributed real-time control system for packet switched networks (

The National Science Foundation (NSF) supported the original research, and evaluated HALO on its network testbed, GENI. HALO supported 300% the throughput at the lowest possible delay between hosts in New York and Sunnyvale, when compared with the prior state-of-the-art. Unlike heuristic protocols, HALO was able to quickly adapt to dynamic traffic changes without prior knowledge.

FIGURE 1: HALO quickly adapted to dynamic traffic changes without prior knowledge

HALO was further tested in the AT&T SDN Network Design Challenge, where competitive solutions were deployed on a prototypical carrier network in the face of rapidly rising dynamic traffic demand. HALO delivered a near-optimal solution in thirty seconds.

FIGURE 2: HALO optimized this AT&T network in thirty seconds for a first-place finish

Mode was founded by these same Cornell computer scientists, who built the commercial version, Mode HALO. This allows Mode — and Mode alone — to deliver the theoretical limit of network routing.