Abstract-In overlay networks, both local and long-distance links appear as a single hop to a routing protocol. Traditional routing metrics (based on hop count or packet loss) fail to take the differences between such links into account. In this paper, we study a metric based on packet delay that has been designed to improve routing in overlay networks. We show a lightweight technique for measuring delay asynchronously, and show how to use the data it provides for constructing a routing metric. Using delay naively leads to persistent routing oscillations, so our routing protocol implements a number of features to bound the frequency of oscillations. We show that our protocol causes no oscillations in real-world tests, and has oscillations with a period on the order of minutes in artificially constructed worstcase setups.
Babel enhances DSDV and other ad-hoc routing protocols and for usage in overlay network it replaces TTLbased routing metric with a delay-based routing metric REF .
A delay-based routing metric
ArXiv
ArXiv
Computer Science