7th International eVLBI Workshop The research network serving for eVLBI applicationCSTnet Jun.2008Xiaodan Zhang

7th International eVLBI Workshop Outline Introduction on CSTnet Testing and demo for eVLBI Challenge and thought

7th International eVLBI Workshop Development and resource

7th International eVLBI Workshop Export Resource

7th International eVLBI Workshop Incoming resources

7th International eVLBI Workshop

Gloriad DV-NOC c.htmlhttp://dev.gloriad.org:8080/viz/dvnoc/dvno c.html

7th International eVLBI Workshop Background of BJLight Its built base on the project of CNGI Having optical fiber connections with nearly 30 national science and technology networks cover many scientific areas A exchange center on scientific data in China Provide a platform and be a Promotion to national and international scientific cooperation and Application Expansibility: abundant resources, dark fibers in Beijing(N*10G)

7th International eVLBI Workshop Resources on Many Scientific Areas China Earthquake Data Center China meteorological Data Sharing Network China topography Science Data Sharing Network China Forestry Data Sharing Network Data-Sharing Network of Earth System Science Network of Science on State Land and Resource Sustainable Development Information Center Geognosy and Mineral Resource Data Sharing Network Chinese Medical and Health Network China Communications Science Network Basic Science Date Center Advanced Manufacturing and Automation Network China Hydrology Science Network Chinese Academy of Agriculture Sciences Network China environmental Science Network Chinese Area Integration science and technology Data Sharing Network National Science and technology Library Network Research of Petroleum Processing Network National Center for Nanoscience and Technology Network National Metrology Science Network China Academy of Railway Sciences Network China Water Resources and hydropower Research Network Genomics Science Network China Academy of Telecommunication Technology Network Network of Chinese Center for Disease Control and Prevention Chinese Academy of Social Sciences Network Architectural Design Science Network

7th International eVLBI Workshop Structure of BJLight

7th International eVLBI Workshop

Light path for eVLBI

7th International eVLBI Workshop Light path status Beijing 2.5G 10G 2.5G HK Seattle Chicago Gloriad-US 2.5G 10G 2.5G 10G Beijing HK Seattle L.A. AU 2.5G 10G 2.5G HK Seattle Chicago Netherlands CN-AU eVLBI Jun.2008 CN-EU eVLBI Aug.2007 CN-US Gloriad May.2006

7th International eVLBI Workshop Encapsulation problem and solution Beijing Seattle HKL.A.AU Parkes, Mopra 2.5G 10G 2.5G 10G Sheshan, SH Cant support VCAT Drop in HK by VC4-4C 16VC4 VCAT VC4-4C 4*vc4 VC4-4C

7th International eVLBI Workshop End to End Testing Severs software Sever NameFacility TypeSystem Kernel ShangHai severMark5red hat smp BeiJing severIBM x3650Debian Hong Kong severDell 2850Debian Iperf version Parameter TCP windows size: 16M UDP bandwith:512M

7th International eVLBI Workshop Test result for Sheshan and Parkes BeiJing Hong Kong Seattle Parkes Los Angles Honolulu ShangHai SH BJ L3 Network TCP 930Mbps LP 0% BJ HK 622M Light path TCP 490Mbps LP 0% HK AU 622M Light path TCP 495Mbps LP 0%

7th International eVLBI Workshop Real-time Test Result on Jun 5

7th International eVLBI Workshop Factors affecting the transmission rate Network environment Terminal Sever System Kernel Network Transfer Protocol

7th International eVLBI Workshop Network Environment Hong Kong Seattle Mopra Los Angeles Honolulu Chicago Singapore

7th International eVLBI Workshop Result Network EnvironmentProtocolspeedJitterLoss packet L3 Network TCP295 Mbits/sec-- UDP509 Mbits/sec0.025 ms1.5% 622M Light path TCP495 Mbits/sec-- UDP535 Mbits/sec0.024 ms0%

7th International eVLBI Workshop Terminal Cases Sever NameFacility TypeCpumemoryEthernet card Beijing Sever 1DellIntel 3.2GHZ2GB Beijing Sever 2IBM x3650Double Intel 3.2GHZ4GBIntel Integrated Card Hong Kong sever Dell 2850Double Intel 3.2GHZ4GBIntel (R) Pro/1000 MF Sever NameFacility TypeSystem Kernel Shanghai severMark5Debian Debian BeiJing severIBM x3650Debian

7th International eVLBI Workshop Network Transfer Protocol and other factors TCP Reliable Not so good bandwidth Fair Poor for long delay UDP No ACK Stable and high bandwidth Little data loss but OK Outstanding for long delay

7th International eVLBI Workshop Challenges and Thought

7th International eVLBI Workshop what we need? Realtime Long baseline between many telescopes 1000km ~ 20000km No data loss, Some losses are tolerable High speeds 128Mbps 256Mbps 512Mbps 1024Mbps, more is better Smooth, little jitter

7th International eVLBI Workshop How to do it ? (1) Transmit protocols UDP maybe is a logical solution Many researcher focus on it and make it applicable to all VLBI hardware and software Add some congestion control capabilities Traditional multiple routes is hard to control, Light paths more better. Light path is still have problem, If point to point light path down ….what you can do? Hybrid network Can we do some improves on our current network, Efficiency is important, can t expand it blindly.

7th International eVLBI Workshop How to do it ? (2) Distributed framework distributed correlation Parallel recording on hardware Network traffic control Dynamic Optical Networking And so on

7th International eVLBI Workshop Thanks!