ResTP Nguyen, Rohrer, Sterbenz A Transport Protocol for ...€¦ · ITTC ResTP Nguyen, Rohrer, Sterbenz A Transport Protocol for Future Internet Resilience 28 March 2015 Anh Nguyen,

Nguyen, Rohrer, Sterbenz ITTC ResTP A Transport Protocol for Future Internet Resilience

28 March 2015

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|[email protected]

© 2015 Nguyen!

Nguyen, Rohrer, Sterbenz ITTC

ResTP Outline

•  Introduction and motivation •  Related work •  ResTP architecture •  AeroTP – subset of ResTP •  Conclusions and future work

28 March 2015 ResTP 2


ResTP Introduction and Motivation

•  Introduction and motivation •  Related work •  ResTP architecture •  AeroTP - subset of ResTP •  Conclusions and future work



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)



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



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



Introduction and Motivation ResTP

•  ResTP –  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



Introduction and Motivation ResTP

•  ResTP –  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



ResTP Related Work




ResTP 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 ResTP



ResTP Related Work

•  Others: –  TP++ composability –  Stream Control Transmission Protocol (SCTP) –  Multipath TCP (MPTCP)



ResTP ResTP Architecture

•  Introduction and motivation •  Related work •  ResTP architecture

–  ResTP cross-layering in the protocol stack –  ResTP header –  ResTP supported services

•  AeroTP – subset of ResTP •  Conclusions and future work



ResTP Architecture ResTP Cross-Layering






ResTP ResTP Cross-Layering

•  ResTP –  receive service spec & threat model

•  from application

–  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

28 March 2015

path char!

dials!knobs!

{ss, tm}

GeoDivRP!

ResTP!

App!

{k,d,[h,t ]}

K32

D74

D43

D32

ResTP 14


ResTP Architecture ResTP Header






ResTP Architecture ResTP 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)

28 March 2015

r!

sequence number!timestamp!

mode! payload length!

destination port!source port!

payload!

flags!ECN!

ResTP 16


ResTP Architecture ResTP Supported Services






ResTP 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)



ResTP 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



ResTP 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



ResTP 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



ResTP AeroTP – subset of ResTP




ResTP AeroTP – subset of ResTP

•  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]



ResTP AeroTP vs. TCP: Average Throughput

•  TCP & AeroTP-ARQ –  back off with BER

•  AeroTP-ARQ –  outperforms TCP

•  significantly



ResTP AeroTP vs. TCP: Average Delay

•  TCP E2E delay –  doubles at BER = 10-4

•  AeroTP-ARQ E2E delay –  small increase



ResTP AeroTP vs. TCP: Cumulative Overhead

•  AeroTP-ARQ –  much less overhead than TCP

•  AeroTP-FEC –  significant overhead

•  delay unaffected



ResTP AeroTP vs. TCP: Data Delivered

•  AeroTP-ARQ –  delivers nearly all data with high BER

•  AeroTP-FEC –  less losses

•  than TCP, UDP •  with high BER



ResTP Conclusion and Future Work




ResTP Conclusions & Future Work

•  Conclusions –  ResTP designed with

•  all resilient-related aspects considered •  assumption of challenged underlying network environments •  goal to support various application classes

•  Work in progress –  completing detailed design of ResTP

•  Future work –  implement ResTP in ns-3 –  analyze ResTP in comparison with TCP, SCPS-TP, MPTCP –  implement prototype



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 66045-7612, Technical Report ITTC-FY2006-TR-45030-01, February 2006

2.  [Rohrer-2009] Justin P. Rohrer, Ramya Naidu, and James P. G. Sterbenz. “Multipath at the transport layer: An end-to-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 2009.

3.  [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):2742—2765, October 2011.

4.  [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, 2012.

5.  [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 2014

6.  [Ford-2013] A. Ford et al. “TCP Extensions for Multipath Operation with Multiple Addresses”. RFC 6824 (Experimental), Jan. 2013

7.  [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 1996. 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, 1993.

9.  [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 737—745, Orland, FL, November 2012.



ResTP Questions?


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ResTP Nguyen, Rohrer, Sterbenz A Transport Protocol for ...€¦ · ITTC ResTP Nguyen, Rohrer, Sterbenz A Transport Protocol for Future Internet Resilience 28 March 2015 Anh Nguyen,