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This article discusses CERNET2's experiences with DVTS (Digital Video Transport System) trials, including configuration, data flow, reflector development, traffic monitoring, and user-controlled testing tools. Lessons learned and summary of the trials are also provided.
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CERNET2 DVTS Experiences Congxiao Bao congxiao@cernet.edu.cn Tsinghua University, CERNET 2007-4-24
Outline • Introduction • CERNET2 DVTS Experiences • Configuration • Data flow • Reflector development • Traffic monitoring • User controlled testing tools • Lessons learnt • Summary
CERNET Video Experiences IPv4 unicast and multicast 38 GigaPops in 36 cities 2,200 universities connected Self-funded operation High utilization (70%+) H.323 AccessGrid DVTS Easy if multicast ready Easy if multicast ready Not Easy Easy
CERNET2 Video Trial Pure IPv6 National Backbone 25 GigaPops in 20 cities 120 universities connected Free usage Low utilization (10%) • DVTS (30Mbps) - Distance learning • HDTV(27Mbps) - for VoD • SDTV-uncompressed (280Mbps) - for interactive VC • HDTV-uncompressed(1.2Gbps) - for interactive HDVC • 3D DVTS(60Mbps) - for special demo
Our Thinking • DVTS is a good application • Popular globally • special demand for network support • 30Mbps, single video stream • Solve the DVTS transmission problem may help for solving other HP transmission problems • Especially for inter-domain case • CERNET2 provides a test-bed • IPv6 • large scale distributed DVTS collaborative environment DVTS is a good starting point!!!
CERNET2 DVTS Trial • Connection topology • Node configuration • Data flow • Reflector development • Traffic monitoring • Website support • User controlled testing tools
BJ 25 DVTS nodes (diameter is about 1000+ kms) Bidirectional transmission 750Mbps DVTS DVTS DVTS DVTS DVTS PKU SY CHC HAB BUPT DVTS DVTS DVTS DVTS DL BUAA TJ DVTS DVTS JN THU ZZ SH LZ DVTS HF DVTS XA DVTS FDU DVTS WH DVTS CHQ DVTS DVTS DVTS NJ DVTS DVTS CD SJTU TJU DVTS CHS DVTS HZ XM DVTS DVTS GZ CERNET2 DVTS Connection Topology
CERNET2 DVTS Node configuration CERNET2 R SW DVTS Testing server DVTS sender DVTS receiver
DVTS configuration— Ordinary Node CERNET2 backbone From reflector Uni.’s video • Other uni.’s videos 30Mbps 30Mbps Sender Receiver display
13 receivers 12 receivers backup Reflector array R R R 30Mx25=750Mbps Reflector array Each reflector receives multicast/unicast stream from sender and converts to 12(13)unicast duplicated copies to 25 different IPv6 hosts distributed in 25 Pops GE switch T640 CERNET2 Multicast/unicast sender THU sending Node configuration—Central Node (1)
xmn bj pku chq xa cd hzh wh bupt chs sy zhz buaa gz dln chc hef nj fdu tjn tju hrb jnn sh lzh PAD display array PC cluster Each PC receives a DVTS stream from one of the 25 Pops, respectively CERNET2 GE T640 switch PC cluster 30Mx25=750Mbps THU Receiving Equipment Configuration— Central Node (2)
Data Flow CERNET2 25 DVTS nodes DVTS receiving DVTS sending SJTU XJTU PKU JLU JLU …… …… CERNET2 CERNET2 GE GE R R R R R R GE GE switch switch switch switch … … SJTU 北大 PKU … … DVTS receiving CERNET2 national Center THU CERNET2 national center THU … … DVTS sending … … 吉大 网管 JLU NMS DV DV
reflector reflector reflector S source unicast SSM multicast Reflector Development • It runs on Linux OS and developed using g++ • It supports IPv4 and IPv6 • It supports Unicast and multicast (SSM and ASM) • It can reflects 20+ streams with gigabit network card • It will be released as Open source soon
User-controlled Testing tools (1) • Open and share the network-application test statistics both for administrators and end-users • Common language • To do the test automatically with the test server at any time without partners • testing servers setup • To do the trouble-shooting hop by hop • Distributed servers in each AS discovery and management
User-controlled Testing tools (2) • Key techniques • Testing server • Web-server • Easy access • Dvping • UDP packet/port 8000 (source-destination)/addr(source-destination)/30Mbps • Dvmcast • For DVTS file receiving • For DVTS real streaming echo • Distributed servers management • Dvbeacon • Dvping, internal 1 test/hour
Web server dvmcast http://202.179.242.102:8056/index.html User: tein2 Pass: tein2 dvping User Controlled Testing Support (3)
dvbeacon dvping monitoring
Lessons learnt (1) • Large-scale DVTS is possible • Network limitation • 30 nodes for unicast • Much more for multicast • PC limitation • CPU/Ethernet card • Integrated tools is very important for trouble-shooting • Isolate network problem and application problem • to do the test hop by hop • Open and share the testing statistics for the administrators and system engineers and end-users • Relieve the load of face-to-face test
Lessons Learnt (2) • Non-technique factors • POC list • Find the right person ASAP • Website • Standard configuration manul • Test reports release • Sharing info on common problem solving • Important notice
Summary • Large-scale DVTS video platform • Unicast • Pure IPv6 • Multiple reflectors with multicast feed • Multicast very soon • Large-scale application-specific measurement system • User controlled pre-test tools • Real time network traffic monitoring