Loss Fluctuations and Temporal Correlations in Network Queues

TL;DR

This paper investigates how buffer capacity and packet-dropping policies cause significant loss rate fluctuations at critical points in network queues, using two different random walk models.

Contribution

It introduces two models of network queues demonstrating critical behavior and analyzes how boundary conditions induce loss fluctuations independent of data arrival variability.

Findings

Loss fluctuations peak at critical points in queue models.

Boundary conditions significantly influence loss behavior.

Critical transitions lead to strong loss rate variability.

Abstract

We consider data losses in a single node of a packet-switched Internet-like network. We employ two distinct models, one with discrete and the other with continuous one-dimensional random walks, representing the state of a queue in a router. Both models {have} a built-in critical behavior with {a sharp} transition from exponentially small to finite losses. It turns out that the finite capacity of a buffer and the packet-dropping procedure give rise to specific boundary conditions which lead to strong loss rate fluctuations at the critical point even in the absence of such fluctuations in the data arrival process.