ResTP A Transport Protocol for Future Internet Resilience

Transcription

1 A Transport Protocol for Future Internet Resilience Anh Nguyen, Justin P. Rohrer, and James P.G. Sterbenz Department of Electrical Engineering & Computer Science Information Technology & Telecommunications Research Center The University of Kansas annguyen rohrej 28 March Nguyen!

2 Outline Introduction and motivation Related work architecture AeroTP subset of Conclusions and future work 28 March

3 Introduction and Motivation Introduction and motivation Related work architecture AeroTP - subset of Conclusions and future work 28 March

4 Introduction and Motivation Issues in TCP TCP & UDP dominant transport protocols in the Global Internet Fragility in performance of network applications end-user experience far from optimal emerging of new applications & use paradigms mobile ad-hoc networks (MANETs) disruption- and delay-tolerant networks (DTNs) wireless mesh networks (WMNs) wireless sensor networks (WSNs) 28 March

5 Introduction and Motivation Issues in TCP TCP limitations due to assumptions behind its design designed for wired networks wireless networks exhibit higher BER assume stable E2E path challenged networks frequently partitioned low delay underlying network high latency increase probability of multiple losses delay TCP reaction to changing network conditions assume single best path between hosts take advantage of multiple paths essential for resilience 28 March

6 Introduction and Motivation TCP Improvement Approaches Modify TCP TCP variants: Westwood(+), Peach, Illinois temporary solution addressing a specific issue Extend TCP normally accomplished through TCP options 40-byte for options limit extensions TCP SACK with only 3-available SACK blocks Develop new transport-layer protocol 28 March

7 Introduction and Motivation Resilient Transport Protocol designed based on ResiliNets framework broad definition of resilience cover multiple disciplines survivability, fault-, disruption-, and traffic- tolerance dependability (reliability & availability), security, performability robustness, complexity first protocol designed with all aspects of resilience 28 March

8 Introduction and Motivation resilient (delay/disruption tolerant), composable, multipath support various application classes across diff. networks provide multiple transport-layer services multiplexing/demultiplexing, flow management error control, transmission control (flow/congestion) multipath spreading each service comprised of multiple mechanisms support cross-layering behavior tuned by applications operation influence/adjusted based on feedback from network capable of taking advantage of multiple diverse paths 28 March

9 Related Work Introduction and motivation Related work architecture AeroTP subset of Conclusions and future work 28 March

10 Related Work Challenged or intermittently-connected networks DTN Architecture Bundle Protocol TCP Convergence Layer (TCPCL) Licklider Transmission Protocol (LTP) SCPS-TP for space communications different mechanisms for different sources of loss new loss-tolerant header compression hybrid SNACK acknowledgement option supported by 28 March

11 Others: TP++ composability Related Work Stream Control Transmission Protocol (SCTP) Multipath TCP (MPTCP) 28 March

12 Architecture Introduction and motivation Related work architecture cross-layering in the protocol stack header supported services AeroTP subset of Conclusions and future work 28 March

13 Architecture Cross-Layering Introduction and motivation Related work architecture cross-layering in the protocol stack header supported services AeroTP subset of Conclusions and future work 28 March

14 Cross-Layering receive service spec & threat model from application {ss, tm} determine/adapt mechanisms & resilient services based on app needs request GeoDivRP calculate k d-geodiverse paths satisfy [h, t] stretch and skew establish multipath E2E flow using k d-geodiverse paths actual data transfer knobs! {k,d,[h,t ]} K 3 2 App!! GeoDivRP! path char! dials! D 7 4 D 4 3 D March

15 Architecture Header Introduction and motivation Related work architecture cross-layering in the protocol stack header supported services AeroTP subset of Conclusions and future work 28 March

16 Architecture Header Mode: transfer mode: flow + error control ERA (multipath erasure coding), ARQ, FEC, (HARQ) CRC, CON (connection), OPT (opportunistic), CT (custody xfer) MSB to LSB fully reliable: 0x2C (ARQ, CRC, CON bits are set) r! source port! destination port! sequence number! timestamp! mode! ECN! flags! payload length! payload! 28 March

17 Architecture Supported Services Introduction and motivation Related work architecture cross-layering in the protocol stack header supported services AeroTP subset of Conclusions and future work 28 March

18 Supported Services Flow Management Connection oriented (CON=1) 3-way handshake (TCP-like) opportunistic (OPT=1) data overlap setup messages E2E ACKs (CT=0) vs. e2e ACKs with custody xfer (CT=1) Connectionless (CON=0) individual datagrams (UDP-like) 28 March

19 Supported Services Error Control ARQ (automatic repeat request) (ARQ=1 & FEC=0) for reliable data transfer alternative ACK schemes ACK, MACK (Multiple), NACK, SACK, SNACK Adaptive FEC (forward error correction) (ARQ=0 & FEC=1) for quasi-reliable data transfer HARQ (Hybrid ARQ = ARQ + FEC) (ARQ=1 & FEC=1) reliable data transfer with E2E FEC No error control (ARQ=0 & FEC=0) for highly loss tolerant applications 28 March

20 Supported Services Transfer Modes Combination of flow management & error control fully reliable: 3-way handshake & E2E ACKs nearly reliable: custody transfer at GWs with E2E ACKs quasi reliable: E2E FEC to achieve statistical reliability unreliable connection: connection oriented best effort unreliable datagram: connectionless best effort 28 March

21 Supported Services Multipath Spreading Data transfer using multiple physical paths paths selected are geo-diverse GeoDivRP multihomed hosts support multiple modes actively spreading data over all selected paths use one active, others hot standby for rapid failover selection of modes based on path attribute, application type, mission requirements 28 March

22 AeroTP subset of Introduction and motivation Related work architecture AeroTP subset of Conclusions and future work 28 March

23 AeroTP subset of AeroTP (Aeronautical Transport Protocol) domain-specific highly-dynamic airborne telemetry network environment opportunistic flow management and 5 transfer modes simulations show better performance than TCP in ns-3 open-source simulator [TAES 2011, MILCOM 2012] 28 March

24 AeroTP vs. TCP: Average Throughput TCP & AeroTP-ARQ back off with BER AeroTP-ARQ outperforms TCP significantly 28 March

25 AeroTP vs. TCP: Average Delay TCP E2E delay doubles at BER = 10-4 AeroTP-ARQ E2E delay small increase 28 March

26 AeroTP vs. TCP: Cumulative Overhead AeroTP-ARQ much less overhead than TCP AeroTP-FEC significant overhead delay unaffected 28 March

27 AeroTP vs. TCP: Data Delivered AeroTP-ARQ delivers nearly all data with high BER AeroTP-FEC less losses than TCP, UDP with high BER 28 March

28 Conclusion and Future Work Introduction and motivation Related work architecture AeroTP subset of Conclusions and future work 28 March

29 Conclusions designed with Conclusions & Future Work all resilient-related aspects considered assumption of challenged underlying network environments goal to support various application classes Work in progress completing detailed design of Future work implement in ns-3 analyze in comparison with TCP, SCPS-TP, MPTCP implement prototype 28 March

30 References 1. [Bhattacharjee-2006] B. Bhattacharjee, K. Calvert, J. Griffioen, N. Spring, and J. Sterbenz, Postmodern internetwork architecture, Information and Telecommunication Center, 2335 Irving Hill Road, Lawrence, KS , Technical Report -FY2006-TR , February [Rohrer-2009] Justin P. Rohrer, Ramya Naidu, and James P. G. Sterbenz. Multipath at the transport layer: An endto-end resilience mechanism. In Proceedings of the IEEE/IFIP International Workshop on Reliable Networks Design and Modeling (RNDM), pages 1-7, St. Petersburg, Russia, October [Rohrer-2011] J. P. Rohrer, A. Jabbar, E. K. Centikaya, E. Perrins, and J.P. Sterbenz. Highly-dynamic cross-layered aeronautical network architecture. IEEE Trans. Aerospace and Electronic Systems, 47(4): , October [Sterbenz-2012] J.P.G. Sterbenz, D. Hutchison, E.K. Centinkaya, A. Jabbar, J.P. Rohrer, M. Scholler, and P. Smith, Redundancy, Diversity, and Connectivity to Achieve Multilevel Network Resilience, Survivability, and Disruption Tolerance (invited paper), Springer Telecommunication Systems, [Yufei-2014] Yufei Cheng, and James P.G. Sterbenz, GeoDivRP Routing with Path Jitter Requirement under Regional Challenges, IEEE/IFIP Sixth International Workshop on Reliable Networks Design and Modeling (RNDM 14), Barcelona, Spain, November [Ford-2013] A. Ford et al. TCP Extensions for Multipath Operation with Multiple Addresses. RFC 6824 (Experimental), Jan [Durst-1996] R. C. Durst, G. J. Miller, and E. J. Travis. TCP Extensions for Space Communications. In ACM MobiCom 96, pages 15 26, New York, NY, USA, November ACM Press. 8. [Feldmeier-1993] D. Feldmeier. An Overview of the TP++ Transport Protocol Project. In A. N. Tantawy, editor, High Performance Networks: Frontiers and Experience, chapter 8. Kluwer, Boston, MA, USA, [Rohrer-2012]J. P. Rohrer, K. S. Pathapati, T. A. N. Nguyen, and J. P. G. Sterbenz. Opportunistic Transport for Disrupted Airborne Networks. In IEEE MILCOM, pages , Orland, FL, November March

31 Questions? 28 March