Dynamic Link Measurements Using Active Components

Abstract

Abstract. Active and programmable network technologies strive to support completely new forms of data-path processing capabilities inside the network. This in conjunction with the ability to dynamically deploy such active services at strategic locations inside the network enables totally new types of applications. In this paper we exploit these network-side programming capabilities to realise a new active network application that dynamically evaluates network link costs based on in-line traffic measurements. The performance experienced by the data packets (e.g. delays, jitter and packet loss) along network or virtual links is used to compute link costs based on multiple cost metrics. The results are published by means of a routing metric broker, which enables available routing protocols to calculate different sets of routes for different QoS metrics -as for example suggested for ToS-based routing (RFC 1583).

Passive Network Awareness as a Means for Improved Grid Scheduling

“…gloperf [4] and DI-ANA [11]) are widely used for their high reliability and accuracy. The accuracy of such tools is in fact not as guaranteed due to the preludial effect: during times of increased load, metrics computed using a probe that preludes a real flow could vary considerably from those experienced by the real flow itself [12,13].…”

Router primitives for programmable active measurement

“…The payload of an IPMP packet consists of path records (e.g., timestamps, interface IP addresses) that can be added by routers as the packets are forwarded. Similarly, Pezaros et al discuss extensions to a IPv6-based "active network" software router designed to augment packets with passively collected measurement data (e.g., to add timestamps to packets as they are forwarded through the software router) [11].…”