Travis Kimes
5536446

The Physical Evolution of the Internet

Introduction

The Internet has evolved through the efforts of thousands of people over more than 30 years of development. It has changed immensely since its conception, and is still changing today. Many of these changes required physical modifications. The Internet has become faster, more secure, and more widespread than ever before. To make these improvements, there have been dramatic changes to the access, structure, and underlying technology that make up the modern Internet. The backbone of the Internet has changed from a few wires connecting four computers to thousands of fiber optic links connecting the entire world. The users have gone from university research departments to teenagers browsing the web on their cell phones. These days you don’t even need to plug into the Internet because many areas have wireless access. Security has always been a problem, but firewalls and advanced routers have made the Internet safer. None of these advances would be possible without the physical evolution of the Internet.

Backbone

One of the first major computer networks ever created was ARPANET. When it was first conceived its speed was going to be 2.4Kbps. After an ACM conference in 1967 it was decided the speed would be 50Kbps. Initially there were only four hosts and they were connected using a Honeywell minicomputer as a switch. This network was managed by ‘Interface Message Processors’ or IMP’s that were connected to the Universities’ main computers. In 1970 Bob Metcalfe developed a 100Kbps network to connect MIT to the Arpanet. New nodes were added to the network about once a month, and by 1974 there were about 23 hosts. In 1976 the network was expanded using satellites (SATNET) and eventually radio connections (PRNET). The host count had risen to over 100. In 1981 that number nearly doubled when the national science foundation introduced CSNET, a 56Kbps network that gave access to hosts unable to connect to ARPANET. ARPANET was divided in 1984 to create MILNET. MILNET was used for military purposes only while ARPANET remained primarily research oriented. Later in 1986 the NSFNET backbone was created at an amazing speed of 1.5Mbps (T1). By this time there were several thousand hosts. Just a few years later (1990) NSFNET was upgraded to T3 (45Mbps). At that time several vendors were using 100Mbps technology and 1Gbps networks were already being developed. The original ARPANET backbone was destroyed and replaced with NSFNET. There were several hundred thousand hosts by the end of 1990. In 1992 the host count grew to over one million. T3 remained the dominant technology until 1994 when asynchronous transmission mode (ATM) line were developed with a speed of 145Mbps. By then there were nearly four million hosts. MCI began upgrading the Internet backbone in 1996 and brought the speed up to 622Mbps. In 1998 Gigabit Ethernet became a standard and many backbones were upgraded. Canada installed the first national optical network (CA*net) in 1998. In 1999 MCI/WorldCom followed by starting to replace its US backbone with 2.5Gbps optical networks.

Users

Although the government and universities have been connected since the beginning, consumers haven’t been able to connect to the Internet until fairly recently. In 1992 Delphi became the first national commercial Internet service provider (ISP). Since that time many other ISP’s such as America Online, Prodigy, and CompuServe have provided millions of people with dialup connections to the Internet. Modems allow users to connect to the Internet through phone lines to the modem pools of the ISP. Between 1991 and 1998 modem speeds jumped from 14.4Kbps to 28.8Kbps, to 33.6Kbps and finally 56Kbps. Surprisingly conventional modem speeds have not progressed beyond that speed due to FCC regulations and physical limitations of phone lines. But of course our need for speed didn’t end there. Broadband was introduced around 1997 with cable modems as the first available option. Cable Internet offers speeds between 300Kbps and 1500Kbps and is transmitted over existing cable television connections. In 1999 DSL (digital service line) was a competitor for the broadband market. DSL was delivered over phone lines, but on much higher frequencies than human voice. This allows for phone and Internet usage simultaneously. DSL is capable of speeds up to 786Kbps, but is often asynchronous with upload speeds at a fraction of the download speed. Satellite Internet was introduced later, but never took much of the broadband market. The Internet was so popular that it began showing up in hotel rooms, cruise ships, and airlines. Mobile phone companies began offering Internet access through cell phones. Internet access has become more affordable too, with several companies offering free dialup access to users willing to tolerate extra advertising. With availability of Internet to almost anyone, the Internet grew very fast. So fast that ISPs feared they would run out of IP addresses. It was speculated that network appliances would be introduced that would require everyone’s microwave, stereo, and air conditioning to have its own IP address. IPv6 was developed to meet this need and an emergency switch was expected from IPv4, but fortunately network appliances never caught on and growth rates slowed. IPv6 will still be necessary eventually, but not as soon as expected.

Wireless

The only thing better than plugging into a wall and connecting to the world is not plugging into the wall and still connecting to the world. With computers and other high tech devices getting smaller and more mobile, the idea of wireless connectivity was extremely appealing. Although long distance wireless networks have been around since the early beginning, short range general purpose wireless networks have not been around until recently. In 1997 the 802.11 standard was created by the Institute of Electrical and Electronic Engineers (IEEE). Two years later the 802.11b standard was created and wireless networking products were introduced. Its maximum speed is 11Mbps, but real world results are usually less. Although 802.11b showed great promise, it suffered from major security problems that slowed its adoption. Large companies and careful consumers feared their networks and data could be compromised remotely from streets or parking lots. In 2002 the 802.11a standard was introduced by the IEEE followed in 2003 by the 802.11g standard. The new standards were many times faster than 802.11b (up to 54Mbps), but had many of the same security flaws as 802.11b. Newer encryption and authentication methods have been developed that make these networks suitable for public access points and general purpose home networks. Many libraries, coffee shops, and bookstores offer wireless Internet access for free or limited cost. The range of these networks is only several hundred feet, but faster, more widespread networks are on their way.

Security

It didn’t take long before someone figured out the Internet could be used for malicious purposes. The first well known virus was introduced back in 1986. The first Internet worm came only two years later and affected nearly 10% of the Internet hosts. This of course made it necessary for the development of Internet security. After the Morris worm the Computer Emergency Response Team (CERT) was formed to advise uses of possible threats. In 1990 the first anti-virus software was developed. Between 1988 and 1992 the number of virus attacks went from five to over one thousand. It wasn’t until 1993 that firewalls were developed. Instead of relying on software for security, firewalls provide a physical piece of hardware that separates the computer(s) from the Internet. Firewalls are an integral part of nearly every network because they provide protection from unwanted external threats by blocking outside requests. In 2000 a new threat came in the form of denial of service (DoS) attacks. These attacks essentially flood networks with traffic and block valid traffic from reaching the victimized host. In 2002 these attacks were escalated with distributed denial of service attacks (DDoS). Distributed attacks use multiple machines to launch a simultaneous attack on one or most hosts. In response to these attacks and many others there have been many advances in routing and network management.

Local Networks

Another logical extension of the Internet is local networks. Having every computer in an organization connected directly to the Internet is wasteful and can lead to management and security problems. A much more reasonable configuration is to connect all of the organization’s computers together in a local network (intranet) and allow secured and possibly restricted access to the Internet through one or more Internet gateways or proxies. Local networks became widespread after Ethernet was developed in 1976. Most organizations and many homes use local networks to make Internet access easier and safer. Large corporations use local networks to keep their data and hardware safe behind elaborate firewalls. Local networking at home allows every computer in the house to share resources and connect to the Internet safely.

Conclusion

The Internet has already been spreading at an exponential rate and there is no reason to believe it will ever slow down. People are finding new ways of using it every day. Speeds continue to increase and our demand seems to increase just as fast. Methods for connecting to the Internet are becoming more innovative, convenient, and widespread. It is only a matter of time before every person, device, and building is connected to the Internet constantly, wirelessly, and at extremely fast speeds.

References

Computer History Museum [Online] Available: http://www.computerhistory.org/exhibits/internet_history/

Kristula, Dave (March 1997) The History of the Internet [Online] Available: http://www.davesite.com/webstation/net-history.shtml

The Evolution of the Internet [Online] Available: http://afrinet.intnet.mu/competition/competition/team02/evolution/main.htm

Bellis, Mary Modem History [Online] Available: http://inventors.about.com/library/inventors/blmodem.htm

Bellis, Mary The History of Ethernet [Online] Available: http://inventors.about.com/library/weekly/aa111598.htm

Leiner et al A Brief History of the Internet [Online] Available: http://www.cs.ucsb.edu/%7Ecs176a/handouts/history.html

Gast, Matthew (2002) Wireless LAN Security: A Short History [Online] Available: http://www.oreillynet.com/pub/a/wireless/2002/04/19/security.html