johnh: research teaching PAPERS software other contact about

Modeling the Performance of HTTP Over Several Transport Protocols

John Heidemann, Katia Obraczka, and Joe Touch
USC/Information Sciences Institute

Abstract

This paper considers the interaction of HTTP with several transport protocols, including TCP, Transaction TCP, a UDP-based request-response protocol, and HTTP with persistent TCP connections. We present an analytic model for each of these protocols and use that model to evaluate network overhead carrying HTTP traffic across a variety of network characteristics. This model includes a analysis of the transient affects of TCP slow-start. We validate this model by comparing it to network packet traces measured with two protocols (HTTP and persistent HTTP) over local and wide-area networks. We show that the model is accurate within 5% of measured performance for wide-area networks, but can underestimate latency when the bandwidth is high and delay is low. We use the model to compare the connection-setup costs of these protocols, bounding the possible performance improvement. We evaluate these costs for a range of network characteristics, finding that setup optimizations are relatively unimportant for current modem, ISDN, and LAN users but can provide moderate to substantial performance improvement over high-speed WANs. We also use the model to predict performance over future network characteristics.

Availability

This paper is available in several formats: abstract web page with pointers and cites, gzip'ed postscript, PDF, paper copies can be obtained by mail to the authors. Copyright terms for this paper appear below.

Reference

Heidemann96a: John Heidemann, Katia Obraczka, and Joe Touch. Modeling the Performance of HTTP Over Several Transport Protocols. To appear, IEEE/ACM Transactions on Networking 5(5), October 1997. November, 1996. <http://www.isi.edu/~johnh/PAPERS/Heidemann96a.html>.

@unpublished{Heidemann96a,
	author = "John Heidemann and Katia Obraczka and Joe Touch",
	title = "Modeling the Performance of {HTTP} Over Several
                        Transport Protocols",
	note = "To appear, IEEE/ACM Transactions on Networking
                         5(5), October 1997",
	seealso = "Heidemann97b",
	year = "1996",
	month = "November",
	keywords = "http performance, p-http, t/tcp, ardp",
	copyrightholder = "{IEEE}",
	url = "http://www.isi.edu/~johnh/PAPERS/Heidemann96a.html",
	psurl = "http://www.isi.edu/~johnh/PAPERS/Heidemann96a.ps.gz",
	pdfurl = "http://www.isi.edu/~johnh/PAPERS/Heidemann96a.pdf",
	organization = "USC/Information Sciences Institute",
}

Copyright

This paper is copyright © 1996 by IEEE. Abstracting is permitted with credit to the source. Libraries are permitted to photocopy beyond the limit of US copyright law, for private use of patrons, those articles in this volume that carry a code at the bottom of the first page, provided that the per-copy fee indicated in the code is paid through the Copyright Clearance Center, 27 Congress Street, Salem, MA 01970. For other copying, reprint, or republication permission, write to IEEE Copyrights Manager, IEEE Service Center, 445 Hoes Lane, PO Box 1331, Piscataway, NJ 08855-1331.