Download Network Research and Research Networks

Network Research and
Research Networks
Fred Baker
Cisco Fellow
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© 2005 Cisco Systems, Inc. All rights reserved.
1
The questions I was asked
• Simon asked me to answer the question:
“What types of networks should
eScience be using?”
That’s a big question, and has many
possible answers
• I was also asked: “Which wireless is
better, 3GPP, WiFi, or WiMax? Which
should we deploy?”
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© 2005 Cisco Systems, Inc. All rights reserved.
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Network Research and Research Networks
• Key question before I answer that:
• What are we doing?
Research Networks: production networks that
support science and education
Networking Research: potentially substandard
networks that test networking concepts
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Research Networks
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2005 Cisco
Cisco Systems,
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Inc. All
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Educational Networks
• Examples of these include the NRENS.
Internet2, AARNET, CERNET, SingAREN,
TANET/TANET2, TWAREN, etc
• Services supported:
Educational institutions, including K-12
and University
High end science
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Education Example:
Greek Public School Network
• Built off Greek NREN
(GRNET):
7 GRNET nodes
82 GSN distribution
routers
~10,000 schools
• Each school today has
two IPv4 /30 subnets
Access network
Loopback
NAT interior
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GSN Distribution Network Design
• One GSN distribution network
per GRNET site (7)
• One access server per
distribution network
GRNET
Router
• BGP Routing
Advertises /48 to GRNET, or
GRNET static routes to it
Default route to GRNET
GSN Distribution Network
• OSPF Routing
Distributes to £ 16 POPs in OSPF
Backbone Area or IS-IS L2
Domain
GSN-served Schools
Distributes to ~200 schools from
each POP using OSPF or IS-IS
Stub Area
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GSN In-School network
• Access connectivity:
To GSN
Distribution
Router
Stateful Firewall
ADSL or ISDN
• Servers
External access limited to SMTP/FTP
download/WWW
Additional POP etc access from lab
Additional POP+FTP Upload access from
administrative domain
Intrusion Management
• Labs
Administration
Servers
No external access
• Administration
Student Lab
No external access
Separated from student network
Intrusion Management
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Big Science Example:
Square Kilometer Array
• Continental radio telescope
Hundreds of correlated radio telescopes
~100 sensors per telescope
20 telescopes in a farm
120 telescope farms
O(800 MBPS) data per sensor
Data blocks O(340 Mbytes)
• One potential design:
Software correlator built on distributed
supercomputer, located at antenna farms
Select interesting data,
Correlate components at primary site
Correlate sites at central location
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© 2005 Cisco Systems, Inc. All rights reserved.
9
Network Research
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©
© 2003,
2005 Cisco
Cisco Systems,
Systems, Inc.
Inc. All
All rights
rights reserved.
reserved.
10
Networks for Networking Research
• Examples of these include
The ten NSF-sponsored networks of the
mid1980’s, one of which blossomed into
today’s Internet
DARTNET/DARTNET2
CAIRN
CANARIE (NREN, but pioneered concept
of consortium fiber)
US National Lambda Rail
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Interesting side effects of testing - NSFNET
NSFNET:
Congested network resulted in TCP’s
congestion avoidance algorithms
Scenario:
Routers had limited buffering
Traffic routinely exceeded network capacity
Effect:
Congestive collapse drove development of
congestion avoidance procedures
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Interesting side effects of testing - CSNET
CSNET
X.25 network that wrung out TCP
implementations
Scenario:
Edge routers set up X.25 VCs
sufficient to support ambient traffic
Load sharing and HDLC bit stuffing
resulted in significant traffic
reordering
Effect:
Many TCPs had issues handling
disordered traffic
Several TCP implementations got
fixed at that time
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What do I think is important in research?
• I think the network should support the research
being done
I think it should allow for a great deal of flexibility
• To me, that means
Providing a stable production network for GRiD
work
Providing a network that can be changed easily
for localized experiments
Providing lambdas that can be deployed for
special purposes at limited times
Not limiting the network to a single technology
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What is “the right technology”?
• The “right” technology is always the
technology that:
meets current needs and
allows for growth
• Always a value judgment, comparing
merits and demerits against
requirements
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What does Taiwan
have, and how might
we use it?
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Lets look at technologies being tested in
Taiwan today
• Fiber networking
• WiMax
• WiFi
• 3GPP
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Fiber networking
• TANET/TANET2:
台灣大學
中央研究院
東華大學
Taipei
C7609 collaboration
Production
network for common
C7609
中央大學 C7609
C7609
GSR
• TWAREN:
中正大學
交通大學
C7609
C7609
Designed for flexibility in high end science
成功大學
TWAREN
Three networks
in parallel:
GSR
新竹
IP production network
Hsin-chu
清華大學
C7609
GSR
Tainan
暨南大學
IP network
for networking experiments
中興大學
GSR
中山大學
Lambda network available for special uses
C7609
C7609
C7609
C7609
Taichung
High capacity: 10 GBPS
on backbone paths
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WiMax
• Wide Area Wireless LAN
Nominally 6 km diameter radio cells
Connected with a fiber backbone
Wide area broadband
• Issues
Shared medium, vs DSL/Cable point to point
Signal strength, BER issues common to wireless
Metropolitan/Urban
• Advantages
Potentially cheaper and higher capacity than
DSL/Cable
Mobile user supported
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WiFi
• Local Area Wireless LAN
Hundreds of meter diameter radio cells
Connected to access infrastructure
• Issues
Shared medium, wired is faster
Signal strength, BER issues common to wireless
Home/office area
• Advantages
Potentially cheaper than house wiring
More flexible usage
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3GPP
• Limited access rate general purpose network
2 MBPS within cell, shared among (potentially
many) users
Or, 64 KBPS circuit
• Issues
Low bit rate compared to WiFi/Wimax
• Advantages
Low BER compared to WiFi/Wimax
More predictable access due to CAC
Often available in the countryside
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How we build networks
• Local Policy
I am always in control of my computer and who it can talk
with
Information security may be an issue, both in the network
and on the host
• Access
How I access the “big I” Internet
• Distribution
How an ISP organizes his network to support his
customers
• Core
The Information Superhighway
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My home network diagram
The Internet
Cable Modem Access Network
Family
Network
Home Office
Network
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How do I go to work?
Broadband
Access/Distribution
Network
Core Fiber
Network
VPN Connectivity
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How I might use Taiwan’s networks
• Security Model:
Wired gives speed/reliability, wireless gives
flexibility
Home or corporate network has defense in depth
Perimeter security (firewall)
Intrusion management
End system security
• Requirements
Ease of network use
Control of resources
Controlled access to sensitive materials
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How I might use Taiwan’s networks
• Local network Solution
WiFi and wired networks in the home/office
• Access solution:
DSL, Cable Modem, or Wimax
Choice depends on price, capabilities, and
availability
• For my uses,
combine wired with all three wireless
approaches,
giving different security and access capabilities
depending on location
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So which is better?
• Each is, for its purpose
• The biggest fallacy in the networking
industry: “one size fits all”
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Research Fallout of Wireless solutions
• Next generation TCP/SCTP procedures
are being developed for improved
performance in wireless and long delay
networks
• A network that combines commercial
service and elevated probability of loss
will require, and will test, those
procedures
• Think of CSNET’s contributions…
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Network Research and
Research Networks
Fred Baker
Cisco Fellow
Session Number
Presentation_ID
© 2005 Cisco Systems, Inc. All rights reserved.
29