1. Enabling New Applications with Optical Circuit-Switched Networks Xuan Zheng April 27, 2004

2. 2 Outline Background and problem statement Proposed RESCUE service Application I: High-speed optical Dial-Up Internet access service using RESCUE circuits Application II: end-to-end RESCUE circuits to improve file transfer delays Implementation of application II Summary

3. 3 Background Current optical network architectures Current optical network applications Leased access circuits for enterprise users High-speed inter-switch/inter-router circuits

4. 4 Gaps between User Needs and Current Network Solutions Access link bottleneck problem Date rates of access links are still slow. Access links are often heavily utilized. TCP limitations TCP is not suited for High-Delay-Bandwidth-Product (HDBP) networks because of its congestion control scheme. Hard to create end-to-end connections to provide QoS for interactive real-time applications Current Internet is connectionless.

5. 5 Prior work In packet-switched networks Packet-switched ring (RPR) is proposed for access links Increasing the circuit rate does not help a lot if the packet loss rate remains high. TCP enhancements are proposed to achieve high end-to-end TCP throughputs HighSpeed TCP, Scalable TCP, FAST TCP, etc. Did not touch the shared nature of Internet; no end-to-end QoS guarantee. QoS in IP based networks IntServ, DiffServ, TCP switching, etc. Implemented at IP routers instead of end hosts. Not scalable, especially when traffic is large.

6. 6 Prior work In circuit-switched networks Traditionally, bandwidth-on-demand is primarily focused on inter-switch/inter-router circuits in service provider networks. Fast restoration and rapid provisioning Centralized resource management with human interventions Latest efforts on bandwidth-on-demand UCLP in Canarie network, ESnet, etc. Provide user-controlled end-to-end optical circuit provisioning Still centralized approach Applications are limited to the elephant data transfer and other eScience applications in a small community Too costly Does not scale for commodity service

7. 7 Problem Statement Design new network architectures exploiting advances in optical switching technologies to bridge the gaps between user needs and network limitations. High-speed circuit switches Dynamic distributed control with signaling/routing protocols

8. 8 Other Enterprises Proposed Architecture: Reconfigurable Ethernet/SONET Circuits for End Users (RESCUE) SETUP SUCCESS Second leased line Second NIC Software upgrade

9. 9 RESCUE: An “Add-on” Service to Primary Internet Access Two paths between two entities: the primary TCP/IP path and an Ethernet/SONET circuit. Packet-switched Internet End host I End host II Optical Circuit- switched Network “Parallel-hybrid” architecture vs. traditional “sequential-hybrid” architecture

10. 10 RESCUE: Applications High-speed optical Dial- Up Internet access service End-to-end file transfers Gap #1 Gap #2

11. 11 Application I: Dial-Up Internet Access Service using RESCUE Circuits

12. 12 Application II: End-to-end RESCUE Circuits to Improve File Transfer Delays Use new transport protocols other than TCP on end-to-end RESCUE circuits

13. 13 Application II: Analytical Basis for the Routing Decision - Delay Analysis

14. 14 Application II: Analytical Basis for the Routing Decision - Delay Analysis

15. 15 Application II: Analytical Basis for the Routing Decision - Delay Analysis

16. 16 Application II: Analytical Basis for the Routing Decision -Delay Analysis T prop = 0.1msT prop = 50ms

17. 17 Application II: Analytical Basis for the Routing Decision - Delay Analysis For example: Crossover file size=180KB P b =0. 3 + P loss =0.01

18. 18 Application II: Analytical Basis for the Routing Decision - Utilization Analysis Symmetric three-link network model

19. 19 Application II: Analytical Basis for the Routing Decision - Utilization Analysis Access link utilization u access Core link utilization u core 93% 84%

20. 20 Analytical Basis for the Routing Decision In low propagation-delay environments Delay-based decision Crossover file size depends upon the link rates and the loading conditions on the two paths In high propagation-delay environments Utilization-based decision A lower bound is needed for crossover file size

21. 21 Implementation of Application II End-host RESCUE software A high-speed transport protocol module for end-to-end file- transfer applications, A routing decision module, A signaling module.

22. 22 High-speed Transport Protocol: Design Rationale Flow control: rate-based scheme to achieve high circuit utilization. Implementation is not trivial. Error control: selective-Automatic-Repeat-reQuest (selective-ARQ) scheme to achieve a high efficiency. Negative Acknowledgements (NAK) because of the guaranteed in-sequence delivery of data blocks on dedicated circuits. Positive Acknowledgements (ACK) are still needed to update sender’s retransmission buffers. Dual communication paths Use primary TCP/IP path to transport reverse-path control messages. Our transport solution: Fixed Rate Transport Protocol (FRTP).

23. 23 High-speed Transport Protocol: FRTP Specification The model of FRTP connections

24. 24 High-speed Transport Protocol: An Implementation of FRTP protocol FRTP is implemented as an application-level process using a combination of UDP and TCP.

25. 25 High-speed Transport Protocol: An Implementation of FRTP protocol Experimental environment: Connections: Two Dell Precision 650 workstations connected via a Dell PowerConnect Gigabit Ethernet switch. Hardware configurations: A 2.4-GHz Intel CPU connected to a 533-MHz front-side bus (34Gbps CPU bandwidth), An E7505 chipset with 512MB of DDR 266MHz memory (17Gbps memory bandwidth), An 80GB ATA/100 7200 RPM EIDE disk drive with 2MB cache (400Mbps average access rate measured by Bonnie [66]), and, A 64bit/100MHz PCIx bus for the GbE NIC (6.4Gbps network bandwidth). The operating systems: RedHat Linux 9 with version 2.4.20-30.9 kernel.

26. 26 High-speed Transport Protocol: An Implementation of FRTP protocol Experimental results with default settings 256KB UDP buffer size, 1500Bytes DATA packet size, 40MB FRTP buffer size, and 8MB block size for disk I/O operations. FRTP throughputFRTP packet-loss rate

27. 27 High-speed Transport Protocol: An Implementation of FRTP protocol Impact of UDP buffer size 500Mbps sending rate, 1500Bytes DATA packet size, 40MB FRTP buffer size, and 8MB block size for disk I/O operations. FRTP throughputFRTP packet-loss rate

28. 28 High-speed Transport Protocol: An Implementation of FRTP protocol Impact of FRTP DATA packet size 500Mbps sending rate, 256K UDP buffer size, 40MB FRTP buffer size, and 8MB block size for disk I/O operations. FRTP throughputFRTP packet-loss rate

29. 29 Routing Decision Module Design

30. 30 Signaling Module Design A RSVP-TE implementation

31. 31 Contributions New network architecture “Parallel-hybrid” instead of traditional “sequential-hybrid” Dedicated end-to-end high-speed connectivity between end hosts Distributed, dynamic end-to-end circuit provisioning instead of centralized resource management. Objective: a large-scale network providing commodity services High aggregate network utilization Commodity services: the elephant data transfer as well as small data transfer High traffic load -> high utilization -> low cost Call blocking mode with packet-switched back-up paths. High circuit utilization Superfast provisioning: distributed + hardware signaling High-speed rate-based flow control Leveraging current conditions of Ethernet and SONET Circuit-switched SONET are widely deployed in wide-area networks. Ethernet dominates local-area networks.

32. 32 Publications from this work Journal papers: M. Veeraraghavan and X. Zheng, “A Reconfigurable Ethernet/SONET Circuit Based Metro Network Architecture,” IEEE JSAC on Advances in Metropolitan Optical Networks (Architectures and Control), 2004. M. Veeraraghavan, X. Zheng, W. Feng, Hojun Lee, E. Chong, and H. Li, “Scheduling and transport for file transfers on high-speed optical circuits,” JOGC on High Performance Networking, 2004. Conference papers: X. Zheng, M. Veeraraghavan, and H. Lee, “Using Dial-Up Optical Circuits to Address the Access Link Bottleneck Problem,” Under revision based on reviews from Infocom 2004. Best Student Paper Award, M. Veeraraghavan, X. Zheng, H. Lee, M. Gardner, and W. Feng, “CHEETAH: Circuit-switched High-speed End-to-End Transport ArcHitecture,” Proceeding of Opticomm 2003, Dallas, TX, Oct. 13-16, 2003. T. Moors, M. Veeraraghavan, Z. Tao, X. Zheng, R. Badri, Experiences in automating the testing of SS7 Signaling Transfer Points, International Symposium on Software Testing and Analysis (ISSTA), July 22-24, 2002, Via di Ripetta, Rome - Italy. Magazine paper: M. Veeraraghavan, D. Logothetis, and X. Zheng, “Using dynamic optical networking for high-speed access,” Optical Networks Magazine, special issue on “Dynamic Optical Networking around the Corner or Light Years Away?”, vol. 4, no. 5, pp. 30-40, Sep. 2003. Workshop papers: M. Veeraraghavan, H. Lee, and X. Zheng, “File transfers across optical circuit-switched networks,” PFLDnet 2003, Geneva, Switzerland, Feb. 3-4, 2003.

33. 33 Questions? Thanks!