CERNET2 DVTS Experiences

Congxiao Baocongxiao@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

•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

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SJTU

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CD

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CHQ

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PKUBUPT

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DVTS DVTS DVTS

DVTS

DVTS

DVTS

DVTSDVTS

DVTS

DVTS

DVTSDVTS

DVTS

DVTS

DVTSDVTS

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CERNET2 DVTS Connection Topology

CERNET2 DVTS Node configuration

CERNET2 CERNET2

DVTSsender

DVTS Testing server

R

SW

DVTSreceiver

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

Video Wall

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

Network Traffic Monitoring

Website Support

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

dvping monitoring

• dvbeacon

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

Thank you!