Transcript Terena 2004

Networking Support for Collaborative Virtual Reality
Projects in National, European and International
Context
TERENA Conference 2004
Rhodes, Greece
7-10 June, 2004
Eva Pless, Ferdinand Hommes
Fraunhofer Institute for Media Communication
Context of work - Projects
Networking support of Virtual Reality projects
 ProViT
- Digital product development with virtually
cooperating teams
- German national project between five
Fraunhofer Institutes
- http://www.provit.net/
 DHX
- Digital artistic and ecological heritage
exchange
- European IST project with Belgian, German,
Greek, Italian partners
- Korea as Asian partner
- http://www.eurasian-dhx.org/
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Context of work – Virtual reality system
Avango – Virtual Environment Framework
 Object-oriented framework for Virtual Reality
applications
 Based on SGI Performer
 Focus on high-end, real-time, virtual environments
like CAVE, i-CONE and responsive workbench
 Binding to Scheme language
 Supports distributed applications
 Distribution based on Maestro/Ensemble API
 Data transmission via IP/UDP unicast and
multicast
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Focus of networking support
Support of distributed applications
 Transmission of model data
 Exchange of synchronization and control data
 Live streaming
Display
Display
3D Objects
Remotely Guided
Character
Sync 3D Objects
Control Data
3D Objects
Remotely Guided
Character
Interaction and
communication model
Video PiP
Audio
Real Guide
Audio/Video
Observers
Observers
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Focus of networking support
Support of remote collaboration
Fraunhofer IMK Screen
 Audio/video conferencing
- Personal communication
- Transmission of screen
pictures
 Remote computer control
- Transmission of slides
KIST Screen
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Networking issues
- Data exchange via IPv4 Internet connectivity
- IP unicast and multicast connectivity required by applications
- Multicast services not provided by some service providers involved
UOC
34
Mbps
RENATER
Greece
France
2 x 622 Mbps
FhG-IMK
155
Mbps
Proxy
IPT
Avango1
GRNET
2,5
Gbps
DFN
internal IPT
Avango net
2,5 Gbps
TEIN
34 Mbps
GEANT
internal ZGDV
Avango net
Avango1
10 Gbps
Germany
Avango1
Proxy
ZGDV
Europe
KOREN
BARCO
2
Mbps
Korea
7,5 Gbps
WorldCom
155 Mbps
National/Europe
ABILENE
tunnel
network
Proxy
IPK
internal IMK
Avango net
GARR
Legend:
Italy
x
National Research Network
x
Project Partner
34 Mbps
Proxy
IMK
Avango-n
10 Gbps
24 Mbps
Avango2
1 Gbps
Japan
622 Mbps
UNIMI
KIST
JGN
USA
CNR
155 Mbps
internal IPK
Avango net
internal IGD
Avango net
Avango1
Avango1
Proxy
IGD
Revised: Januar 2004
DHX topology
ProViT multicast tunnel
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Advanced networking issues
QoS trials between European partners
 GÉANT network offers Premium IP (PIP) service
 Link to University of Crete totally overloaded
 Several NOCs had to be contacted
 Package overhead of 25 % has to be considered
IMK WS
FhG
IMK
IMK WS
PIP service
DFN
Bottleneck
restricted access bandwidth
(25 Mbps)
GEANT
PIP-Service 2 Mbps
Dedicated bandwidth 2 Mbps
Normal IP Traffic
GRNET
UOC
WS
UOC
UOC
WS
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Advanced networking issues
IPv6 connectivity to Korea via TEIN link
 Dedicated 5 Mbps connection with low traffic
 Tunnelling of IPv6 over IPv4 within Germany
 Tunnelling of IPv4 over IPv6 as not all applications support IPv6
Bottleneck
(dedicated bandwidth
for IPv6)
University
of Münster
router
GWiN
IPv4
FhG
Campus
IPv4
GWiN
IPv6
GEANT
IPv6
RENATER
IPv6
TEINlink
KOREN
Router
IPv6-over-IPv4tunnel
IPv4-over-IPv6tunnel
KOREN
IPv4
KOREN
IPv6
KIST
IPv4
KIST
IPv6
FhG router
IMK
IPv6
IMK
IPv4
IPv6
IPv4
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Networking tools
- Monitoring
 nsl, iptraf
 Multi Router Traffic Grapher (MRTG)
- Reachability and routing
 ping
 trace, mtrace
- Package capturing
 ethereal
- Service providers provide multicast
beacons, looking glasses and interface
graphs
 Problem: restricted access
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Performance measurement
- Tools
E1 \ E2
 NetIQ Qcheck and Chariot, iperf Bonn
- Type of measurements
 Throughput
 Response time
 Streaming emulation
- Jitter, data loss
Pisa
Milano
Crete
Seoul
Date/Time
2901-15:21
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2901-15:21
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2901-15:21
0202-11:32
2901-15:21
0202-11:32
2901-15:21
0202-11:32
Bonn
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Pisa Milano Crete Seoul
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528
- Problems
 Results depend on network and
workstation configuration
 Changes of the network
configuration und usage
Results from DHX
response time tests
(ms)
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Networking experience – security and firewall
- Private network protection
 Opening of the firewall for agreed addresses
- Problem: each address change has to be discussed with all partners
 Opening special ports
- Problem: overhead in application configuration
 Positioning of gateways outside the firewall
- Problem: Security policies of companies
- Virtual Private Networks
 Different service providers, different technologies
- Restriction of multicast traffic in private networks
 Avoidance of overload by multicast traffic
 Restricted multicast group access not yet available
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End-user Problems
- Restricted access bandwidth of private networks (financial restrictions)
- Missing multicast know-how
- Responsibility of application developer and networking personal
- Missing interest in networking of application developers
Traffic graph February 2003:
Link to the University of
Crete
incoming from UOC
outgoing to UOC
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Benefits and problems in European and international context
FhG-IMK
Institut
- Research networks offer more services than commercial
networks
- Research networks are better prepared to fulfil advanced
requirements of end-users
- Living networks are dynamically adapted to changing
necessities and technological progress
- If problems arise, a number of different administrative units has
to be addressed to solve them
- Tools are needed that help non-expert users to see the state
of the network at a glance
FhG Campus
GWiN
national NOC
GÉANT
European NOC
GRNET
national NOC
UOC
Campus
UOC-CSD
Institut
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Conclusion
- Virtual interaction and collaboration will be important topics in the next years
- Research networks will be the first that offer advanced services (Grid,
Bandwidth on Demand, Quality of Service, Advanced multicast features)
- Security issues have to be considered that do not restrict collaboration
- In distributed projects all partners should plan the engagement of networking
specialists
- NOCs should provide tools to allow end-to-end network analysis and
performance monitoring
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