HAASP: History-Aware Adaptive Shortest-Path Routing for Software-Defined Networks
TL;DR
This work presents HAASP (History-Aware Adaptive Shortest-Path), a closed-loop SDN routing controller that composes static topology weights, decaying load memory, and decaying fault memory into a single bounded cost.
Abstract
Load-aware routing in Software-Defined Networking (SDN) has two structural limitations: path selection is based on instantaneous link utilization, forcing oscillations in routing as the controller makes decisions that perturb the measurements driving them; and this instantaneous view cannot capture the time-scale over which link reliability accumulates. We present HAASP (History-Aware Adaptive Shortest-Path), a closed-loop SDN routing controller that composes static topology weights, decaying load memory, and decaying fault memory into a single bounded cost. A hysteretic state machine adapts the decay coefficient to network conditions without itself oscillating, and a per-flow migration hysteresis bounds route-change rates. We introduce the Path Stability Index (PSI), a byte-weighted per-flow stability metric, and prove closed-form bounds on penalty growth, path stretch, convergence, and PSI. HAASP is evaluated against five baselines (static Dijkstra, ECMP, EWMA-smoothed routing, CFR-RL, DRSIR) across four topologies, four failure scenarios, and a full hyperparameter sweep, with a scalability study to 200 nodes.