Delay Performance in IP Routers

Document type: Conference Papers
Peer reviewed: Yes
Full text:
Author(s): Patrik Carlsson, Doru Constantinescu, Adrian Popescu, Markus Fiedler, Arne A. Nilsson
Title: Delay Performance in IP Routers
Conference name: 2nd International Working Conference (HET-NETs '04)
Year: 2004
City: Ilkley
Organization: Blekinge Institute of Technology
Department: School of Engineering - Dept. of Telecommunication Systems (Sektionen för teknik – avd. för telekommunikationssystem)
School of Engineering S- 372 25 Ronneby
+46 455 38 50 00
Authors e-mail:,,,,
Language: English
Abstract: The main goals of the paper are towards an understanding of the delay process in best-effort
Internet for both non-congested and congested networks. A dedicated measurement system is re-ported
for delay measurements in IP routers, which follows specifications of the IETF RFC 2679.
The system is using both passive measurements and active probing. Dedicated application-layer
software is used to generate UDP traffic with TCP-like characteristics. Pareto traffic models are
used to generate self-similar traffic in the link. The reported results are in the form of several impor-tant
statistics regarding processing delay of a router, router delay for a single data flow, router delay
for more data flows as well as end-to-end delay for a chain of routers. We confirm results reported
earlier about the fact that the delay in IP routers is generally influenced by traffic characteristics,
link conditions and, at some extent, details in hardware implementation and different IOS releases.
The delay in IP routers usually shows heavy-tailed characteristics. It may also occasionally show
extreme values, which are due to improper functioning of the routers.
Subject: Telecommunications\General
Keywords: traffic measurements, delay performance, IP routers, traffic self-similarity