Analysis of Measured Single-Hop Delay from an Operational Backbone Network

— We measure and analyze the single-hop packet delay through operational routers in a backbone IP network. First we present our delay measurements through a single router. Then we identify stepby-step the factors contributing to single-hop delay. In addition to packet processing, transmission, and queueing delays, we identify the presence of very large delays due to non-work-conserving router behavior. We use a simple output queue model to separate those delay components. Our step-by-step methodology used to obtain the pure queueing delay is easily applicable to any single-hop delay measurements. After obtaining the queueing delay, we analyze the tail of its distribution, and find that it is long tailed and fits a Weibull distribution with the scale parameter, ¼ , and the shape parameter, ¼ to ¼ . The measured average queueing delay is larger than predicted by M/M/1, M/G/1, and FBM models when the link utilization is below 70%, but its absolute value is quite small.

• Type: Conference
• Year: 2002
• Where: INFOCOM
• Authors: Konstantina Papagiannaki, Sue B. Moon, Chuck Fraleigh, Patrick Thiran, Fouad A. Tobagi, Christophe Diot
• Keywords: Communications, Delay Measurements, INFOCOM 2002, Single-hop Delay, Single-hop Packet Delay