Multipath TCP in SDN-enabled LEO Satellite Networks Pengyuan Du, Sobhan Nazari, Jorge Mena, Ruolin Fan, Mario Gerla, Riten Gupta Department of Computer Science, UCLA, USA
Outline Introduction Satellite SDN Architecture MPTCP-SDN Framework Simulation Conclusion
Outline Introduction Satellite SDN Architecture MPTCP-SDN Framework Simulation Conclusion
Introduction Low Earth Orbit (LEO) satellite networks Example Global coverage High bandwidth Energy-efficient Broadcasting Backhaul Example Iridium Teledesic
TCP: large delay, low throughput Introduction Challenge Frequent satellite handover Every 10 min Interrupt voice or video app Long RTT Hundreds of millisecond TCP: large delay, low throughput
Related Work High Bandwidth Delay Product TCP [1] Hybla Cubic Westwood Multipath TCP (MPTCP) [2] Improve throughput Soft handover [3] [1] Caini, Carlo, Rosario Firrincieli, and Daniele Lacamera. "Comparative performance evaluation of tcp variants on satellite environments." ICC. IEEE, 2009. [2] Ford, Alan, et al. Architectural guidelines for multipath TCP development. No. RFC 6182. 2011. [3] Paasch, Christoph, et al. "Exploring mobile/WiFi handover with multipath TCP." CellNet. ACM, 2012.
Related Work MPTCP is an extension to TCP which lets you use multiple paths simultaneously Path manager, scheduler To manage a Multipath TCP connection that uses several paths TCP subflows To transport data Congestion control To control congestion over multiple paths
MPTCP socket Multipath TCP TCP1 TCP2 TCPn ... Application Application Transport TCP1 TCP2 TCPn Network ... Datalink Physical
MPTCP Data transmission ABCDEF socket socket Multipath TCP Two levels of sequence numbers ABCDEF socket socket Multipath TCP Multipath TCP Data sequence # TCP1 TCP1 TCP1 sequence # TCP2 TCP2 sequence # TCP2
MPTCP in Satellite Network The idea in [1] The circled number 1-4 indicates the order of 4 handovers occurred to each sub-flow. [1] Du, Pengyuan, Xiao Li, You Lu, and Mario Gerla. "Multipath TCP over LEO satellite networks.“ IWCMC. IEEE, 2015.
MPTCP in Satellite Network On-demand Multipath Source Routing (OMSR) Distributed protocol => control overhead Lacks of inter-satellite signaling => route conflict Devise a more sophisticated scheme => onboard processing The circled number 1-4 indicates the order of 4 handovers occurred to each sub-flow. [1] Du, Pengyuan, Xiao Li, You Lu, and Mario Gerla. "Multipath TCP over LEO satellite networks.“ IWCMC. IEEE, 2015.
Motivation Replace OMSR with Software-defined Networking (SDN) [1] SDN splits the control and data plane Centralize the design logic Minimize onboard processing Easier computation of disjoint paths Contribution MPTCP+SDN framework for LEO system [1] Kreutz, Diego, et al. "Software-defined networking: A comprehensive survey." Proceedings of the IEEE 103.1 (2015): 14-76.
Outline Introduction Satellite SDN Architecture MPTCP-SDN Framework Simulation Conclusion
Satellite SDN Architecture [1] Bao, Jinzhen, et al. "OpenSAN: a software-defined satellite network architecture." ACM SIGCOMM Computer Communication Review. ACM, 2014. [2] Saxena, Piyush. "Satellite Communication Advancement, Issues, Challenges and Applications." International Journal of Research . 2014.
Outline Introduction Related work & Motivation Satellite SDN Architecture MPTCP-SDN Framework Simulation Conclusion
MPTCP-SDN Framework MPTCP configurations SDN controller Each user has 2 separate interfaces Establish 2 TCP subflows using 1 interface Recently enabled since MPTCP v0.89 The other interface runs in backup mode SDN controller Topology-aware (LLDP) MPTCP-aware Multiple disjoint paths discovery
MPTCP-SDN Framework
MPTCP-SDN Framework
MPTCP-SDN Framework
Outline Introduction Related work & Motivation Satellite SDN Architecture MPTCP-SDN Framework Simulation Conclusion
Simulation Simulation setup Linux Ubuntu 14.04 LEO network Mininet emulator Up/Downlink: 2Mb/s Floodlight remote controller Inter-satellite link: 9Mb/s Link delay: 14ms Kernel MPTCP v0.90 Compare against: TCP Hybla Path manager: fullmesh, num_flows=2 MPTCP+Equal-cost multipath routing (ECMP)[2] Congestion control: balia [2] [1] Peng, Qiuyu, Anwar Walid, and Steven H. Low. "Multipath TCP algorithms: theory and design." ACM SIGMETRICS. 2013. [2] Raiciu, Costin, et al. "Improving datacenter performance and robustness with multipath TCP." ACM SIGCOMM. ACM, 2011.
Simulation Results Throughput of MPTCP with SDN
Simulation Results
Outline Introduction Related work & Motivation Satellite SDN Architecture MPTCP-SDN Framework Simulation Conclusion
Conclusion Proposed an MPTCP-SDN framework for LEO satellite network MPTCP exploits and manages multiple TCP subflows An MPTCP-aware SDN controller The framework addresses handover by leveraging MPTCP backup mode. Simulation Outperforms single path TCP, MPTCP+ECMP Soft handover
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