View
213
Download
1
Category
Preview:
Citation preview
Copyright © 2011, MBL@CS.NCTU
A Flow-based Hybrid Mechanism to Improve Performance in NOX and wireless OpenFlow
switch networks
Bruno Van Den Bossche, Bart De Vleeschauwer, Tom Verdickt, Filip De Turck, Bart Dhoedt, Piet Demeester
Journal of Network and Computer Applications, vol. 32, no. 6, 2009
Copyright © 2011, MBL@CS.NCTU
Outline
• Overview• Introduction• Problem description• Main Approach • Related Works• Evaluation• Conclusions• Reference
Copyright © 2011, MBL@CS.NCTU
Overview
• In this paper, we propose a flow-based hybrid mechanism to improve performance in NOX and wireless OpenFlow switch networks.
• The main idea of this scheme is that when the transmission of a OpenFlow switch fails, one of neighbor OpenFlow switches transmits the lost frame for the failed one.
Copyright © 2011, MBL@CS.NCTU
Introduction
• If the packet does not match a flow entry or OpenFlow switch fails to transmit its data, OpenFlow switch requests the path to the NOX.
• However, if OpenFlow switch requests the path to NOX whenever it fails to transmit its data, it will be a big overhead in wireless OpenFlow switch networks with a bad channel quality.
Copyright © 2011, MBL@CS.NCTU
Problem Description
• Retransmission of failed data allows other OpenFlow switches to lose their channel access chances and increases the number of Packet-In Message overheads such as packet header, ID assigned by data-path, full length of frame and acknowledgement (ACK) transmission.
Copyright © 2011, MBL@CS.NCTU
Main Approach
• Each OpenFlow switch naturally overhears the transmitted packets of other OpenFlow switches toward the same destination, it buffers the packets that is not yet acknowledged in overhear table.
• Own data table
• Overhear table
Copyright © 2011, MBL@CS.NCTU
Main Approach
Channel Condition α<= β and x<=y α: the total flow size for sending
β: the maximum flow threshold
x : the SNR of failed OpenFlow switch
y : the SNR of current OpenFlow switch
Copyright © 2011, MBL@CS.NCTU
Related Works
• [1] designed a novel relay-enabled DCF protocol to exploit the physical layer multirate capability.
• Data can be transmitted with different rates and some data packets may be delivered faster through a relay.
[1] novel relay- enabled DCF protocol
Flow-based Hybrid Mechanism
overhead
Insufficient to decrease the number of MAC/PHY overhead
Aggregate scheme used in flow transmission to NOX
Copyright © 2011, MBL@CS.NCTU
Conclusion
• It shows that in environments where the packet is likely to be lost more, the throughput gain of our proposed scheme performs better.
Recommended