Transcript The Internet in Real Life A Network Manager`s Perspective

CSE588: Network Systems
Terry Gray*
Director, Networks & Distributed Computing
Affiliate Professor, Computer Science & Engineering
University of Washington
* and friends
Agenda
Week 1: Internet History and Basic Concepts
Week 2: Routing vs. Switching
Week 3: Architecture and Topology Trends
Week 4: Multimedia (QoS, CoS, multicast)
Week 5: ATM vs. IP
Week 6: Routing part 1 (Intro, RIP, OSPF)
Week 7: Routing part 2 (BGP, state of the Internet)
Week 8: TBD --Guest lecture(s)
Week 9: Failure Modes and Fault Diagnosis
Week 10: Product evaluation criteria
Non-Agenda
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Tutorial on Networking Fundamentals
Protocol Design
Device Design
Network Programming
Network Modeling/Analysis
The Plan
• Focus on Internet technology from network
practitioner’s perspective.
• Focus on enterprise and wide-area issues.
• Use commodity Internet and UW campus
network as case studies.
• Discuss and debate alternatives!
Week 1: Background
• Networking Fundamentals
• The Internet: Past, Present, Future
• UW’s Intranet: Past, Present, Future
Networking Fundamentals
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Terminology
The Reference Model(s)
The Great Debates
Conventional Wisdom
Gray’s Networking Nuggets
Some Research Questions
Terminology
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Open
LAN, CAN, MAN, WAN... VLAN, ELAN
TCP/IP
Internet, Intranet
Packet, Message, Circuit Switching
Frame, Cell
Repeater, Bridge/Switch, Router
MAC Address
IP Address
ATM
The Infamous
OSI REFERENCE MODEL
Version 1
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Transport
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The Infamous
OSI REFERENCE MODEL
Version 2
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Religious
Political
Economic
Application
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Cable Plant
<--- You are here
The Internet Reference Model
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Application
Transport
Network
Link
• 1 Physical
e.g. HTTP
e.g. TCP
i.e. IP
e.g. Ethernet
e.g. Fiber
Internet Protocols by Layer
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Application: HTTP, FTP, Telnet, NFS, IMAP, etc
Transport: TCP, UDP, RTP
Network: IP (ICMP, IGMP, DHCP, OSPF)
Link: ARP, RARP
Layers vs. Interoperability
OS
L5
Application
L4
Transport
L3
Network
L2
Link
L1
Physical
BB
Conventional Wisdom
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1988:
1992:
1995:
1995:
1997:
1997:
OSI will replace TCP/IP
Cat 3 wire will never carry 10Mbps
ATM will replace TCP/IP
ISDN will be pervasive
VLANs will replace routers
Telco competition will reduce costs
The Great Networking Debates
circa 1992
• Ethernet vs. Token Ring
• Routers vs. Bridges
• Multi Protocol vs. Single Protocol
• FDDI vs. ATM
• TCP/IP vs. OSI
The Great Networking Debates
circa 1997
• Ethernet vs. ATM
• Routers vs. Switches
• Multi Protocol vs. Single Protocol
• TCP/IP vs. ATM
Design/Deployment Questions
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Requirements (protocols, applications)
Architecture (Topology, technology)
Routing vs. switching vs. hybrids
Device evaluation criteria
Multimedia (QoS, CoS, multicast)
ATM vs. Fast/Gigabit Ethernet
IPv6
Gray's Networking Nuggets
• KISS-1: Keep It Simple, Stupid
“Heterogeneity always costs more than you think it will”
• KISS-2: Keep It Separate, Stupid
“Good fences make good neighbors”
• The last art is the art of glumping
• Design for high-availability...
but beware the dark side of Redundancy
• Technology rots: don't buy it before you need it
Gray's Networking Nuggets
continued
• “Trust but Verify”…
"Acid indigestion? Check your source.”
• Beware standardization by government edict
(Ada, OSI, X.400)
• Standardization always happens too soon
technically, but too late practically
• "Conventional Wisdom" is completely orthogonal
to "Wisdom"
Research Questions
• Performance:
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Transient delay analysis tools
Multi-layer congestion control effects
QOS and COS
TCP, RTP, etc, design improvements
• Topology: Hierarchy, mesh, lattice, ring
• Security: Infrastructure, session/packet
End of Fundamentals
• If the terminology is unfamiliar, hit the books!
• Discussion?
• Next up:
30 years of the Internet in 30 minutes
The Internet: Past, Present, Future
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Introduction
History
Issues
Summary
Introduction: How many of you...
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Use Email almost every day?
Use the Web almost every day?
Consider yourself an "Internet Junkie"?
Plan to become one Real Soon Now! ?
Have seen a TV documentary on the Internet?
Know what the ARPANET was?
See the 'Net as a Really Big Deal?
My view of the Internet:
• A powerful tool, with both good and bad uses.
• An unparalleled sociological phenomenon.
• Both a trigger and a medium for defining 21st
century values.
• Some pretty interesting technology.
POP QUIZ #1 ( True or False):
• The ARPANET was designed to be a military
command/control network that could survive nuclear war.
• Packet switching technology was chosen for ARPANET
primarily because of its ability to go around faulty portions of
a net.
• Packet switching technology was one of the most important
achievements of Bell Labs, and AT&T was an enthusiastic
partner in the ARPANET project.
• Computer Scientists at major universities were universally
supportive of the ARPANET, unlike those at smaller schools.
POP QUIZ #1 ( Cont’d):
• The World Wide Web was invented at CREN (the
Corporation for Research and Educational Networking)
• Email was one of the prime motivators for the net.
• Unlike the telecommunication industry, the computer
industry quickly adopted Internet standards in their quest
to provide open systems.
• Restricting use of encryption on the Internet will ensure
that communication remains open.
POP QUIZ #2 (True or False):
• ARPA projects led not only to today's Internet, but also to
cellular telephone and Ethernet technology.
• The Web is not the Internet.
• The Internet will eliminate many jobs.
• The Internet will create many jobs.
• The Internet is a powerful tool for world peace.
• The Internet is a powerful tool for Western Imperialism.
• In the Internet, the U.S. Constitution is a local ordinance.
The History of the Internet
overview…
• 1960s: The Vision
> Remote Resource Sharing
• 1970s: Making it Work
> Packet switching, LANs, Internets
• 1980s: Widespread Deployment
> NSFnet, Bitnet, CSnet, Usenet, Fidonet
• 1990s: Success Problems
> Scaling, Navigation, Filtering, Politics, Economics
The History of the Internet
highlights…
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1962: Dr. Licklider goes to Washington
1966: Bob Taylor has too many terminals on his desk
1969: ARPANET begins (also Woodstock, Apollo 11)
1972: ARPANET and ALOHANET interconnect
1973: Metcalf/Boggs develop Ethernet from Alohanet
1974: Cerf/Kahn publish TCP/IP specification
1977: TCP/IP demo: ARPANET, SATNET, PRNET,
Ethernet
The History of the Internet
highlights cont’d…
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1979: USENET (distributed BBS) begins
1981: BITNET, CSNET, Minitel begin
1983: ARPANET cutover to TCP/IP completed
1986: NSFNET begins
1988: The Internet Worm attack
1990: ARPANET ends
1991: World Wide Web invented
1993: NCSA Mosaic released
1995: NSFNET ends, Netscape goes public
Why the Internet will Fail
circa 1992
• "TCP/IP is a sunset technology"
• "You can't use TCP/IP for mission critical applications"
• "TCP/IP can't go very fast"
• "FTP will corrupt complex data files"
• "You can't do multimedia over SMTP"
• "TCP/IP is a proprietary protocol developed by DOD"
• "The Internet standards process is not open”
Why the Internet might Fail
circa 1997
• Scaling:
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Addresses,
Routing,
Bandwidth,
DNS
• Function:
– QOS,
– Security
Why the Internet might Fail
non-technical issues
• Threats from policy problems:
– Usage: Censorship, Copyright, Spam/junk
– Micro-economic: distance/time/usage pricing
– Macro-economic: Haves/HaveNots, Investment
• Threats to individuals:
– Privacy: Exposure of info, usage patterns
– Addiction: impact on social contact/activities
– Productivity: signal-to-noise ratio
More Internet concerns...
• Threats from crime:
– Real crime: technology helps the bad guys, too.
– Pseudo-crime: misguided legislation
• Threats to organizations:
– Open communication
– No hierarchy
• Threats to business:
– Some middlemen will be toast
– Legal liabilities will stifle some businesses
More Internet concerns...
• Threats to scholarly quality:
– Content: lots of junk, lots of old versions
– Searching/catalogs: best stuff may never be found
• Shared files/authorship: coordination
problems
The NSFnet is Gone
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NSFnet ceased to exist 30 April 1995
Initially a non-event, but trouble followed.
There is no longer *a* national backbone
MCInet is now carrying >> max NSFnet traffic
MCInet traffic doubling every 4-6 months
MCInet backbone: DS-3 to OC-3 to OC-12
Extrapolation to 2000: Need OC192
The Internet Goes P.C.
• PC = Personal Computer:
– Nov 1994: Bill Gates announces 2 initiatives:
• Investment in UUNET
• Reorientation of Microsoft Network
• PC = Politically Correct:
– Oct 1996: Bill Clinton announces 3 initiatives:
• Internet II
• Next Generation Internet
• Internet 2000
INTERNET II ?
• Is this a government or Higher-Ed initiative?
• What are the goals?
• Will commercial net providers meet Higher-Ed needs?
• How do Higher-Ed needs differ from, say, Chrysler's?
• Will "Virtual University" needs force dedicated net?
• Would it even help to have a Higher-Ed net?
Summary: The Internet...
• Is an amazing tool and an amazing phenomenon.
• Tends to eliminate time, distance, and rank.
• Breeds misinformation on and about it.
• Faces challenges that are growing exponentially.
• Brings opportunities that are growing exponentially.
• The hardest problems ahead are not technical
(but there are some dandy technical problems, too!)
End of Internet: Past, Present, Future
• At least, from a non-technical perspective!
• Discussion?
• Next up: UW Network Overview
UW’s Intranet: Past, Present, Future
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Environment
Growth
Key Decisions
Topology
UW Network: Environment
• 1988: five anti-interoperable campus nets...
– 3,000 machines on a bridged Ethernet
– A large Micom terminal network
– Separate library, hospital, and administrative nets
• 1997: one campus net with...
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12,000 PCs
6,000 Macs
4,000 Unix workstations
3,000 X terminals
1,000 hubs, routers
UW Network: Growth
• By 12/94 we had 17,000 nodes and 650 modems
• By 12/95 we had 22,000 nodes and 1,300 modems
• By 12/97 we had 27,000 nodes and 1,500 modems
• Run-rate had been 3k/yr nodes, now flat…
> Saturation at last??
UW Network: Key Decisions
• Use Internet standards
• Route only IP
• Use lots of subnets
• Use lots of 10BaseT Ethernet
• Move to dedicated/switched 10
UW Network: Backbone Topology
• Epoch 1 (c. 1989): Dual Shared Ethernet Backbones
• Epoch 2 (c. 1992 ): Dual Routers
• Epoch 3 (c. 1995): Quad Ethernet Switches
• Epoch 4 (c. 1998): Quad Fast Ethernet Switches
End of UW Network Overview
• Stay tuned for more on UW network issues!
• Discussion?
• Next up:
– Week 2: Switching and Routing