Solving Ack inefficiencies in 802.11 networks

Author

Murray, David ; Koziniec, Terry ; Dixon, Michael

fYear

2009

fDate

9-11 Dec. 2009

Firstpage

1

Lastpage

6

Abstract

The founding idea behind this study was that 802.11 acks and TCP acks are substantial contributors to 802.11 over-heads, yet, they both provide the same functionality; reliability. Initial experiments suggest that 802.11 acks contribute to over 20% of the overhead in 802.11 networks. Unfortunately, without 802.11 acks, paths with RTTs greater than a millisecond are unable to utilise this additional performance because lost packets, which occur frequently in unacknowledged (NoAck) 802.11, are interpreted as congestion. This study experiments with a range of PEPs (Performance Enhancing Proxies) which retransmit lost packets. A new proxy, known as D-Proxy, designed to solve the shortcomings of previous I-TCP and Snoop proxies, is experimentally developed and tested in Linux. D-Proxy is a distributed, proactive proxy that caches, analyses and resends packets based on TCP sequence numbers. The results suggest that D-Proxy can substantially improve 802.11 throughputs.

Keywords

ad hoc networks; telecommunication network reliability; transport protocols; wireless LAN; 802.11 networks; D-Proxy; Snoop proxies; TCP; ack inefficiencies; multihop ad-hoc networks; performance enhancing proxies; reliability; Data communication; Delay; Error correction; Ethernet networks; Linux; Performance evaluation; Testing; Throughput; Topology; Wide area networks;

fLanguage

English

Publisher

ieee

Conference_Titel

Internet Multimedia Services Architecture and Applications (IMSAA), 2009 IEEE International Conference on

Conference_Location

Bangalore

Print_ISBN

978-1-4244-4792-3

Electronic_ISBN

978-1-4244-4793-0

Type

conf

DOI

10.1109/IMSAA.2009.5439494

Filename

5439494