The Internet: Present Broadband Packet Switching: A Personal Perspective

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The Internet PresentBroadband Packet
SwitchingA Personal Perspective

• 2002.9.2
• Meehwa Kim

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Abstract

• This article represents the authors personal
  perspective on the development of broadband
  packet switching from 1980 to 1995.
• Todays Internet represents 0.1 of the
  deployment of a national petabit broadband packet
  network.
• Along the deployment timeline, the author
  describes the development of packet voice,
  Ethernet bridging, ATM, gigabit testbeds, and
  local ATM.
• Discussing the efforts at transitioning the
  Internet from academic to commercial service

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Introduction

• The author contributed to the development of
  broadband packet switching and its use in the
  modern Internet.
• Two distinct milestones in Broadband packet
  switching
• Voice network ARPANET, U.S. PSTN
• BISDN

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Voice over Ethernet

• D. Sincoskie found that Ethernet would carry up
  to 150 simultaneous voice calls.
• the calls were coded at 64 kbps
• silent periods removed
• This was enough to construct a 1000-line private
  branch exchange (PBX).
• In 1982, D. Sincoskie made a voice over Ethernet
  cal.
• works with PSTN
• incorporated echo cancellers

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Ethernet Bridges

• Problems of Ethernet-based
• It could grow to 1000 phones carrying 200
  conversations, but the system wasnt scalable.
• Ethernet also didnt work over long distances.
• ARPANET in 1983s maximum speed was 56kb/s, less
  than the bit rate of a single packet
  phone(64kb/s).

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Ethernet Bridges

• Ethernet Bridges
• Low-cost high-throughput devices to interconnect
  Ethernets
• Routing seemed slow and complex, due to the
  complexities of the IP protocol.
• VLAN (Virtual LAN)
• Add some field in each packet
• Contribute for scaling multicasting, enabling
  mobility, reducing extraneous broadcasting

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The Challenge ExpandsThe Birth of Broadband

• Synchronous Wideband Switch (SWS)
• 45 Mb/s digital cross-connect system
• Use packet technology at its core
• Basically a circuit switch
• Problems of SWS
• How to resolve contention in a broadband packet
  switch
• How to guarantee end-to-end performance in a
  packet switched network

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Experimental Research Prototype

• Incorporate a broadband circuit switch for voice
  and video applications
• The ERP project demonstrated in 1987.
• A serial input packet switch at 56 Mb/s
• A 240 Mb/s circuit switch
• Packet access multiplexing at 150 Mb/s
• Integrated multimedia services packet voice and
  data, and circuit-switched video

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Making Packet NetworkPerformance Deterministic

• Questions of Packet Switching Performance
• Could packet switching meet the service
  requirement?
• Could packet networks perform like circuit
  networks?
• Circuit Switching
• Strong point extensibility
• Weak point inefficient to multiservice networks
• Packet Switching
• Weak point problem of guaranteeing performance,
  delay and packet loss rate

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Making Packet NetworkPerformance Deterministic

• Solutions
• Multi-rate circuit switching
• Dynamic TDM
• Stop and go queuing
• Packet switching is better than TDM circuit
  switching.

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Eletropolitics

• Big issues of Internet standard
• Packet vs. circuit switching
• Actual packet format
• In 1986, Internet and Ethernet both used variable
  length datagrams with relatively large packet
  headers.
• Fixed-size packet became standard.

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Eletropolitics

• The BISDN carried voice.
• Packet size
• U.S. standard 64 bytes
• Europe standard 16-32 bytes
• Japan standard 66 bytes
• In 1989, ATM 53-byte cell became standard.
• 5-byte header, 48-byte body

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Eletropolitics

• Trend changes
• Ethernet, IP over SONET
• ATM served as an Internet backbone in the 1990s.
• IP over Ethernet over WDM network will be future
  access network.

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Onward to a Gigabit

• CNRI Gigabit testbed
• Four 155 Mb/s lines in parallel achieve 622 Mb/s
  throughput.
• 622 Mb/s full-duplex ATM network could transmit
  data at 1.244 Gb/s in both directions.
• In 1993, project AURORA
• First wide-area ATM/SONET network
• 2.5 Gb/s SONET backbone running from Philadelphia
  to Boston
• 155 and 622 Mb/s ATM host interfaces

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Local ATM

• Ethernet
• Dominant, but inefficient capacity
• FDDI
• 100 Mb/s rate, but not dominant
• ATM
• Scalable, Industry standard for BISDN
• Problems of integrating ATM into TCP/IP protocol
  stack
• Mid-1990s enjoyed market place
• 100 Mb/s speeds

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Local ATM

• Fast Ethernet
• Proposed in 1992
• 100 Mb/s
• Advantage over ATM Software compatible
• Switched VLAN enabled 100 Mb/s.
• Gigabit Ethernet dominate LAN market.

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Commercializing the Internet

• Issues of commercializing
• Commercial network needs multiple backbones.
• Multiple Internet access providers have to be
  accommodated.
• In 1993, NSF offered a new architecture for a
  commercial Internet.
• Define NAP (network access point)
• Multiple backbone
• NSFNET research and education purpose only
• Other commercial backbones

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Conclusion

• In this article, the author said that he want to
  construct a national scale packet-switched
  network supplying 150 Mb/s to every residence.
• In the early 1980s, the ARPANET had a total
  capacity of 10 Mb/s and the PSTN had a terabit
  capacity.
• The total capacity of the U.S. Internet today is
  1 Tb/s.
• The envisioned broadband network would have
  capacity of petabit.