Internet Traffic Modeling. Authors:. Date: 2009-12-09. Why Model Internet Traffic?. Why model traffic? The traffic model is the key for determining the performance of the system. The more accurate is the traffic model the better is the system quantified in terms of its performance.
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Internet Traffic Modeling Authors: Date: 2009-12-09 Vinko Erceg, Broadcom
Why Model Internet Traffic? • Why model traffic? • The traffic model is the key for determining the performance of the system. The more accurate is the traffic model the better is the system quantified in terms of its performance. • Traffic model in the evaluation methodology document should focus on capturing the accents of the application which posts special demand on the system performance. • What is being modeled here? • We are modeling TCP and Web browsing • This document proposes to changes that were presented in IEEE 802.11-09/1216r1. • Why? • Almost all of us use standard simulators such as OPNET, NS2, OMNET etc. • These simulators are rich enough to have most types of TCP inbuilt with all the TCP parameters. • Additionally, we want to include reference to IEEE 802.11n evaluation methodology document Vinko Erceg, Broadcom
Modeling TCP Traffic • Almost all the file transfers between individual devices that are connected via IEEE 802.11 and its extensions happens through TCP. • This is the recommended protocol for all traffic that passes through the IP stack • We consider a simple file transfer. • The file size is fixed at 10 GByte. In this profile the PCP is also an AP and is connected to the backbone. Since the packet size is limited by Ethernet, we set it as 1500 bytes Vinko Erceg, Broadcom
TCP Procotol Configuration The table on the right outlines the TCP configuration in all simulators. All these parameters are available. These were the same parameters that were used in IEEE 802.11n evaluation methodology document. Vinko Erceg, Broadcom
First Packet of Session Reading Time Reading Time Last Packet of Session Modeling HTTP Traffic (1) • HTTP traffic characterization is quite complex and is a function of • Structure of WWW pages and • Nature of human interaction • Based on the above properties, it is bursty and is modeled by ON/OFF sources • ON periods represent the webpages being transferred from the server to client and the OFF periods refers to the reading time of the user • Also a webpage consists of multiple subpages and each main page reference generates the request of those subpages Vinko Erceg, Broadcom
Modeling HTTP Traffic (2) • The parameters of HTTP file transfer are: • SM: Size of main object in page • Nd: Number of embedded objects in a page • SE: Size of an embedded object in page • Dpc: Reading time • Tp: Parsing time for the main page • The table on the right highlights the components and their distributions Vinko Erceg, Broadcom
Conclusions • We have outlined the models of TCP traffic and HTTP traffic to be used for evaluation methodology document for TGad • The TCP traffic is the same as what was done in the evaluation methodology document in IEEE 802.11n • The HTTP traffic is represented by few distributions that have been taken from extensive studies of references [1-6]. Vinko Erceg, Broadcom
References •  P. Barford and M Crovella, "Generating Representative Web Workloads for Network and Server Performance Evaluation" In Proc. ACM SIGMETRICS International Conference on Measurement and Modeling of Computer Systems, pp. 151-160, July 1998. •  S. Deng. “Empirical Model of WWW Document Arrivals at Access Link.” In Proceedings of the 1996 IEEE International Conference on Communication, June 1996. •  R. Fielding, J. Gettys, J. C. Mogul, H. Frystik, L. Masinter, P. Leach, and T. Berbers-Lee, "Hypertext Transfer Protocol - HTTP/1.1", RFC 2616, HTTP Working Group, ftp://ftp.Ietf.org/rfc2616.txt, June 1999. •  B. Krishnamurthy and M. Arlitt, "PRO-COW: Protocol Compliance on the Web", Technical Report 990803-05-TM, AT&T Labs, http://www.research.att.com/~bala/papers/procow-1.ps.gz, August 1999. •  B. Krishnamurthy and C. E. Wills, "Analyzing Factors That Influence End-to-End Web Performance", Computer Networks: The International Journal of Computer and Telecommunications Networking, Volume 33 , Issue 1-6, pp. 17-32, June 2000. •  H. K. Choi, J. O. Limb, "A Behavioral Model of Web Traffic", Proceedings of the seventh International Conference on Network Protocols, 1999, pp. 327-334, November 1999. Vinko Erceg, Broadcom