Abstract
Service prioritization among different traffic classes is an important goal for the Internet. Conventional approaches to solving this problem consider the existing best-effort class as the low-priority class, and attempt to develop mechanisms that provide "better-than-best-effort" service. In this paper, we explore the opposite approach, and devise a new distributed algorithm to realize a low-priority service (as compared to the existing best effort) from the network endpoints. To this end, we develop TCP Low Priority (TCP-LP), a distributed algorithm whose goal is to utilize only the excess network bandwidth as compared to the "fair share" of bandwidth as targeted by TCP. The key mechanisms unique to TCP-LP congestion control are the use of one-way packet delays for early congestion indications and a TCP-transparent congestion avoidance policy. The results of our simulation and Internet experiments show that: 1) TCP-LP is largely non-intrusive to TCP traffic; 2) both single and aggregate TCP-LP flows are able to successfully utilize excess network bandwidth; moreover, multiple TCP-LP flows share excess bandwidth fairly; 3) substantial amounts of excess bandwidth are available to the low-priority class, even in the presence of "greedy" TCP flows; 4) the response times of web connections in the best-effort class decrease by up to 90% when long-lived bulk data transfers use TCP-LP rather than TCP; 5) despite their low-priority nature, TCP-LP flows are able to utilize significant amounts of available bandwidth in a wide-area network environment.
Original language | English (US) |
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Pages (from-to) | 739-752 |
Number of pages | 14 |
Journal | IEEE/ACM Transactions on Networking |
Volume | 14 |
Issue number | 4 |
DOIs | |
State | Published - Aug 2006 |
Funding
Manuscript received September 11, 2003; revised March 28, 2004; approved by IEEE/ACM TRANSACTIONS ON NETWORKING Editor J.-Y. LeBoudec. This work was supported by the National Science Foundation. A portion of this work appears in the Proceedings of IEEE INFOCOM 2003.
Keywords
- Available bandwidth
- Service prioritization
- TCP
- TCP-LP
- TCP-transparency
ASJC Scopus subject areas
- Software
- Computer Science Applications
- Computer Networks and Communications
- Electrical and Electronic Engineering