Using simple per-hop capacity metrics to discover link layer network topology

Abstract

At present, link layer topology discovery methodologies rely on protocols that are not universally available, such as SNMP. Such methodologies can only be applied to a subset of all possible networks. Our goal is to work towards a generic link layer topology discovery method that does not rely on SNMP. In this paper, we will present a new link layer topology discovery methodology based on variable packet size capacity estimation. We will also discuss the problems that arose from preliminary testing where different brands of network cards affected the capacity estimates used to detect serializations. As a result, topologically equivalent links fail to be classified as such by the capacity estimation tool. To circumvent this issue, non-VPS methods of capacity estimation that utilise back to back packet pairs have been investigated as a calibration technique. © Springer-Verlag Berlin Heidelberg 2005.