TY - GEN
T1 - Failure of TCP congestion control under diversity routing
AU - Zhang, Yupeng
AU - Chapin, John
AU - Chan, Vincent W.S.
PY - 2011
Y1 - 2011
N2 - TCP does not perform well in networks with stochastic channels, with links that randomly drop packets or have long outages. Diversity routing has been proposed to improve TCP's performance in these networks. In diversity routing, a sublayer between TCP and the network replicates each transmitted packet and sends the multiple copies along parallel paths. As long as at least one of the copies reaches the receiver, TCP considers the transmission successful and maintains high throughput. Previous investigations of diversity routing have analyzed TCP's performance when there is a single flow and no congestion. In this paper, we analyze the performance of multiple flows in a congested network. The contribution of this work is the discovery of three adverse effects that occur when TCP is combined with diversity routing. The effects are: link capacity overflow, rate unfairness, and lock-out of late-arriving flows. Simulation is used to analyze the root cause of these effects. Our conclusion is that nave diversity routing fundamentally breaks the TCP congestion control mechanism and cannot be used for TCP performance improvement in networks with stochastic channels, such as many wireless and satellite networks. We propose an improvement to diversity routing that may overcome these problems, enabling use of unmodified TCP.
AB - TCP does not perform well in networks with stochastic channels, with links that randomly drop packets or have long outages. Diversity routing has been proposed to improve TCP's performance in these networks. In diversity routing, a sublayer between TCP and the network replicates each transmitted packet and sends the multiple copies along parallel paths. As long as at least one of the copies reaches the receiver, TCP considers the transmission successful and maintains high throughput. Previous investigations of diversity routing have analyzed TCP's performance when there is a single flow and no congestion. In this paper, we analyze the performance of multiple flows in a congested network. The contribution of this work is the discovery of three adverse effects that occur when TCP is combined with diversity routing. The effects are: link capacity overflow, rate unfairness, and lock-out of late-arriving flows. Simulation is used to analyze the root cause of these effects. Our conclusion is that nave diversity routing fundamentally breaks the TCP congestion control mechanism and cannot be used for TCP performance improvement in networks with stochastic channels, such as many wireless and satellite networks. We propose an improvement to diversity routing that may overcome these problems, enabling use of unmodified TCP.
KW - congestion control
KW - diversity routing
KW - network simulation
KW - stochastic networks
KW - transmission control protocol
UR - http://www.scopus.com/inward/record.url?scp=79959306336&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79959306336&partnerID=8YFLogxK
U2 - 10.1109/WCNC.2011.5779225
DO - 10.1109/WCNC.2011.5779225
M3 - Conference contribution
AN - SCOPUS:79959306336
SN - 9781612842547
T3 - 2011 IEEE Wireless Communications and Networking Conference, WCNC 2011
SP - 569
EP - 574
BT - 2011 IEEE Wireless Communications and Networking Conference, WCNC 2011
T2 - 2011 IEEE Wireless Communications and Networking Conference, WCNC 2011
Y2 - 28 March 2011 through 31 March 2011
ER -