e-VLBI and End-to-End Performance

1. APII Workshop 2004 October 28-29, 2004 Capacity C Sender Receiver K5 Data Acquisition Terminal 1～2Gbps lost packet packet train Large Bandwidth-Delay Product Network issue measured packet 256Mbps Queue Size = C x (Delaymax – Delaymin) K3 Correlator (Center) K3 Recorder (Right) K4 Correlator K4 Terminal e-VLBI and End-to-End Performance VLBI (Very Long Baseline Interferometry) Example: From Tokyo to BostonTCP on a fast long path with a bottleneck Analyzing Advanced TCP Dynamic Behavior in a Real Network(Example: From Tokyo to Indianapolis at 1G bps with HighSpeed TCP) • e-VLBI geographically distributed observation, interconnecting radio antennas over the world Tokyosender rate control Bostonreceiver loss detection radio signal from a star Los Angeles queue overflow delay 50ms 50ms bw 0.8G ASTRONOMY GEODESY • Gigabit / real-time VLBI multi-gigabit rate sampling bw 1G loss bottleneck clock A/D A/D clock ~Gbps 100ms ~Gbps feedback Internet Fringe It takes 150ms to know the loss (buffer overflow). It keeps overflowing during the period… 150ms is very long for the high-speed network. 150ms at 1Gbps generates ~19MByte on the wire. correlator The data was obtained during e-VLBI demonstration at Internet2 Member Meetingin October 2003. Replaying in a Laboratory-Evaluation of Advanced TCPs- Example of Advanced TCPswith different bottleneck queue sizes Measuring Bottleneck Queue Sizes BIC TCP queue size 100 packets FAST TCP queue size 100 packets ENP2611Network Processor Emulator GbE GbE SenderLinux 2.4 ReceiverLinux TCP Only 800 Mbps available RTT 200ms(100ms one-way) TCPNewReno(Linux) BIC TCP queue size 1000 packets FAST TCP queue size 1000 packets Switch/Router Queue Size Measurement Result HighSpeedTCP (Web100) VLBI Antenna Locations in North-East Asia Shintotsukawa 3.8m * set to 100M for measurement Nanshan (Urumqi) 25m70km from Urumqi Tomakomai 11m, FTTH (100M)70km from Sapporo Miyun (Beijing) 50m50km from Beijing Seoul 20mYonsei U Nobeyama 45mOC48/ATM Galaxy b) a) Mizusawa 10m 20m118km from Sendai Usuda 64m, OC48/ATM Galaxy Daejon 14mTaeduk Ulsan 20mU Ulsan Experiment for High-Performance Scientific Data Transfer Tsukuba 32m, OC48/ATMx2 SuperSINET 2Mbps Switch Router Switch Router Kashima 34m, 1Gx2 JGN, OC48/ATM Galaxy Koganei 34m, 1Gx2 JGN, OC48/ATM Galaxy 1Gbps Observatory is on CSTNET at 100M Gifu 11m 3m, OC48/ATMx2 SuperSINET 1Gbps Jeju 20mTamna U 100Mbps 1Gbps Kagoshima 6mAira 10m Yamaguchi 32m1G, 75M SINET Sheshan (Shanghai) 25m30km from Shanghai Iriki 20m Typical Bottleneck Cases 2Mbps Seoul XP Ogasawara 20m Chichijima 10m 10G Korea Kashima 100km Ishigaki 20m Daejon bwctl server Legend JGNII KOREN perf server connected 1G (10G) Taegu U of Tokyo SWITCH 2.5G Kwangju not yet connected e-vlbi server Busan Koganei antenna under construction Tokyo XP / JGN II I-NOC 1G 1G(10G) 250km GEANT 2.5G SONET JGN II 10G Summary and Future Work APII/JGNII 7,000km 10G 2.5G Kitakyushu 1,000km 9,000km Chicago MIT Haystack TransPAC 1G 1G (10G) Fukuoka • High-performance scientific data transfer faces on network issues we need to work out. • Big science applications like e-VLBI and High-Energy Physics need cooperation with network researchers. • Deployment of performance measurement Infrastructure is on-going on world-wide basis. • Lessens are shared with CHEP and KAIST experiments over APII and TransPAC as well as CMM (Common Measurement Machines). Abilene 2.4G Pittsburgh Genkai XP Fukuoka Japan 10G 4,000km Washington DC Indianapolis Los Angeles *Performance Measurement Point Directoryhttp://e2epi.internet2.edu/pipes/pmp/pmp-dir.html A BWCTL account available for CMMincluding Korean researchers International collaboration to support science applications Appendix - VLBI System Transitions 2002~ PC-based System Hard-disk Storage Software Correlator e-VLBI over Internet 64Mbps 1st Generation 1990~ Cassette Tape Hardware Correlator e-VLBI over ATM 3rd Generation 1983~ Open-Reel Tape Hardware Correlator 2nd Generation