CERNET2 DVTS Experiences Congxiao Bao congxiao@cernet.edu.cn Tsinghua University, CERNET 2007-4-24.
Post on 18-Dec-2015
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Outline• Introduction• CERNET2 DVTS Experiences
– Configuration– Data flow– Reflector development– Traffic monitoring– User controlled testing tools
• Lessons learnt• Summary
•IPv4 unicast and multicast
•38 GigaPops in 36 cities
•2,200 universities connected
•Self-funded operation
•High utilization (70%+)
CERNET Video Experiences
•H.323 •AccessGrid •DVTS
•Easy •Easy if multicast ready•Easy if multicast ready •Not Easy
•Pure IPv6 National Backbone
•25 GigaPops in 20 cities
•120 universities connected
•Free usage
•Low utilization (10%)
CERNET2 Video Trial
• 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
• 25 DVTS nodes (diameter is about 1000+ kms)
• Bidirectional transmission
• 750MbpsDVTS
DVTS
DVTS
DVTS
DVTS
DVTS DVTS
DVTS DVTS
THU
XA
WH
HF
SJTU
GZ
CD
SY
TJ
CHQ
XM
NJ
LZ
DL
HABCHC
JN
HZCHS
ZZ
PKUBUPT
BUAA
FDU
TJU
DVTS DVTS DVTS
DVTS
DVTS
DVTS
DVTSDVTS
DVTS
DVTS
DVTSDVTS
DVTS
DVTS
DVTSDVTS
BJ
SH
CERNET2 DVTS Connection Topology
DVTS configuration— Ordinary Node
Sender Receiver
CERNET2 backbone
From reflectorUni.’s video
display
30Mbps 30Mbps•Other uni.’s videos
Node configuration—Central Node (1)
R R RReflector
array
sender
switchGE
Multicast/unicast
T640
12 receivers 13 receivers
backup
CE
RN
ET
2
THU sending
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
30Mx25=750Mbps
Equipment Configuration— Central Node (2)
bj wh gz nj sh
xa cd sy tjn lzh
chq chs zhz hef jnn
xmn hzh dln chc hrb
pku bupt buaa fdu tju
PAD displayarray
PCcluster
switchGE
30Mx25=750Mbps
PC clusterEach PC receives a
DVTS stream from one of the
25 Pops, respectively T640
CERNET2
THU Receiving
SJTU XJTU …… JLU
CERNET2
switch switch
……
…
…
北大
吉大 网管
DV
CERNET2 national Center THU
R R RGEGE
CERNET2 25 DVTS nodes
DVTS
sending PKU …… JLU
CERNET2
switch switch
……
…
…
PKU
JLU NMS
DV
CERNET2 national center THU
R R RGEGE
DVTS
sending
DVTS
receiving
DVTS
receiving
SJTU
Data Flow
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
source
reflector
reflector
reflector
SSSM multicast
unicast
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
User Controlled Testing Support (3)
• Web server • dvmcast
• dvping
http://202.179.242.102:8056/index.html User: tein2Pass: tein2
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
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