1. The Internet: Present Broadband Packet Switching: A Personal Perspective 2002.9.2 Meehwa Kim

2. Abstract This article represents the author ’ s personal perspective on the development of broadband packet switching from 1980 to 1995. Today ’ s 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

3. 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

4. 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

5. Ethernet Bridges Problems of Ethernet-based It could grow to 1000 phones carrying 200 conversations, but the system wasn ’ t scalable. Ethernet also didn ’ t work over long distances. ARPANET in 1983 ’ s maximum speed was 56kb/s, less than the bit rate of a single packet phone(64kb/s).

6. 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

7. The Challenge Expands: The 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

8. 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

9. Making Packet Network Performance 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

10. Making Packet Network Performance Deterministic Solutions Multi-rate circuit switching Dynamic TDM Stop and go queuing Packet switching is better than TDM circuit switching.

11. 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.

12. 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

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

14. 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

15. 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-1990 ’ s enjoyed market place 100 Mb/s speeds

16. 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.

17. 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

18. 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 1980 ’ s, 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.