Doc.: IEEE 802.11-09/1317r0 Submission December 2009 Vinko Erceg, BroadcomSlide 1 Internet Traffic...
8
Decembe r 2009 Vinko Erce g, Br Slide 1 doc.: IEEE 802.11-09/1317r0 Submission Internet Traffic Modeling Date: 2009-12-09 Authors: Name Affiliat ions Addres s Phone Email Sai Nandagopalan Broadcom San Diego 858 521 2192 [email protected] Vinko Erceg Broadcom San Diego 858 521- 5885 [email protected]
-
Upload
ruby-mcdaniel -
Category
Documents
-
view
215 -
download
0
Transcript of Doc.: IEEE 802.11-09/1317r0 Submission December 2009 Vinko Erceg, BroadcomSlide 1 Internet Traffic...
December 2009
Vinko Erceg, Broadcom
Slide 1
doc.: IEEE 802.11-09/1317r0
Submission
Internet Traffic Modeling
Date: 2009-12-09
Authors:
Name Affiliations Address Phone Email
Sai Nandagopalan Broadcom San Diego 858 521 2192 [email protected]
Vinko Erceg Broadcom San Diego 858 521-5885 [email protected]
December 2009
Vinko Erceg, Broadcom
Slide 2
doc.: IEEE 802.11-09/1317r0
Submission
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
December 2009
Vinko Erceg, Broadcom
Slide 3
doc.: IEEE 802.11-09/1317r0
Submission
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
December 2009
Vinko Erceg, Broadcom
Slide 4
doc.: IEEE 802.11-09/1317r0
Submission
TCP Procotol ConfigurationTCP Configuration Parameters in Simulators
MSS Ethernet (1500 bytes)
Receive Buffer (Bytes) 65535
Receive Buffer Adjustment None
Delayed ACK Mechanism Segment/Clock based
Max. ACK Delay (Sec) 0.05
Slow Start Initial Count (MSS) 1
Fast Retransmit Enabled
Duplicate ACK Threshold 3
Fast Recovery Reno
Window Scaling Enabled
Selective ACK (SACK) Disabled
ECN Capability Disabled
Segment Send Threshold Byte Boundary
Active Connection Threshold Unlimited
Karn’s Algorithm Enabled
Nagle Algorithm Disabled
Initial Sequence Number Auto Complete
Initial RTO (sec) 3.0
Min RTO (sec) 1.0
Max RTO (sec) 64
RTT Gain 0.125
Deviation Gain 0.25
RTT Deviation Coefficient 4.0
Timer Granularity 0.25
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.
December 2009
Vinko Erceg, Broadcom
Slide 5
doc.: IEEE 802.11-09/1317r0
Submission
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
Reading TimeFirst Packet of Session Last Packet of SessionReading Time
December 2009
Vinko Erceg, Broadcom
Slide 6
doc.: IEEE 802.11-09/1317r0
Submission
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
December 2009
Vinko Erceg, Broadcom
Slide 7
doc.: IEEE 802.11-09/1317r0
Submission
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].
December 2009
Vinko Erceg, Broadcom
Slide 8
doc.: IEEE 802.11-09/1317r0
Submission
References• [1] 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.
• [2] S. Deng. “Empirical Model of WWW Document Arrivals at Access Link.” In Proceedings of the 1996 IEEE International Conference on Communication, June 1996.
• [3] 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.
• [4] 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.
• [5] 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.
• [6] 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.
