On 1999-03-09, Wolf Blitzer had an interview with Gore on CNN's Late Edition. During this interview, Gore said, "During my service in the United States Congress I took the initiative in creating the internet. I took the initiative in moving forward a whole range of initiatives that have proven to be important to our country's economic growth and environmental protection, improvements in our educational system." After hearing this report, Gore introduced legislation during the late 1980s known informally as the Gore Bill [50]. It was passed, however, as the High Performance Computing Act of 1991 [51] on Dec. 9, 1991 and led to the NII or National Information Infrastructure [52] which Gore referred to as the Information superhighway. Funding for the development of MOSAIC in 1993, [60] the World Wide Web browser which is often credited as leading to the Internet boom during the mid-1990s, came from the High-Performance Computing and Communications Initiative, a program created by the High Performance Computing Act of 1991 This quote became the subject of heavy satire [63]. background of computer architecture (25) - operating system: first program run when you turn on the machine, handles running other programs, called application programs - examples, windows, macintosh OS, unix/linux - cpu (brain of the computer) - clock speed - how many instructions can execute in a fixed amount of time - given in MHz or GHz - cycle is the smallest unit of time recognized by the computer's internal clock - may also see MIPS (millions of instructions per second) - instruction set - collection of operations the CPU can execute - very low level - add, subtract, move bits around - distinguishes pentium from G4 from chips made by other manufacturers - this is why programs are designed for certain architectures - word size - amount of data the CPU handles at once during each cycle - MOORE's LAW - computers double in speed every 18 mo without increase in cost - dual core CPU - two complete CPUs that run independently, doesn't always double the "speed" of your computer - memory - many different types, they vary in how long they hold your data - RAM (measured in MB or GB) (off chip, volatile, computer slows down when you don't have enough, from running too many programs at once) - long-term storage (measured in GB) (non-volatile) - allows you to install more programs and save more files (music, movies) - relate to MP3 players (size, cost, can't dance around in some) - adding more RAM can improve speed, disk cannot - Units of Memory [1.3] - Everything on your computer is saved in files; each file has a name (the filename) - Files are constantly being moved across the internet, and different types of application programs work with different types of files. - Files have sizes, corresponding to how much stuff is in them -Data sizes --bit: all data in computer is represented by sequences of bits --8 bits to 1 byte: a sequence of 8 bits is a byte --1 Byte can represent 2^8 pieces of info (256) --KB = 1024 = 2^10 bytes, MB = 1024 KB = 2^20 bytes , GB = 1024 KB = 2^30 bytes - explain power of 2 (1024 versus 1000) - storage sizes of various media (1.44 MB floppy, 650-700MB cdrom, 4.7-17 GB dvd blu-ray = 25 or 50 GB, HD DVD = 15 or 30 GB - rewritable, writeonce, - highres photo -- 500KB music (who has an MP3 player) ask for storage sizes - compressed vs uncompressed - uncompressed ~ 9mb/min - MP3 - 1meg/minute most all information on disk is stored in files -- has a filename [1.4] NETWORKS AND THE INTERNET (35) HISTORY OF NETWORKS and the INTERNET - let's make computers talk to each other 1960s - share data - send email (predated internet 1965) --LAN-local area networks-close together and connected - used by universities, government, large corporations, because only they had computers originally - eventually universities wanted to communicate with each other -- soon they wanted to create communication links between them - dumb terminals and leased lines -- one terminal per connection - had to get up and sit at different ones - [feb 1958] USSR's launch of sputnik spurred USA to create ARPA, later DARPA - one project was to create a single network of computers so that different people in different areas of the country could use each others computers for their ARPA research. - [october 29 1969] first node - UCLA went online - [nov 21 1969] had the first link to stanford - [dec 5 1969] followed by UC santa barbara, and Univ of utah - ARPANET was the core of what was to become the internet - word internet - internetworked (interconnected) networks - commericial use of the internet was originally forbidden, though the definition of "commercial" wasn't well defined. -- commercial networks sprang up to give consumers access to the network of networks in the late 1980s (ISPs) -- First dial-up ISP in 1989. - in 1990 the ARPANET project officially ended, and the backbones (main interconnections) were no longer maintained by ARPA, and the final commercial restrictions were lifted - there was no presentation software, only using the computer from command line and things like email - Tim Berners-Lee, a researcher at CERN (French, European Organization for Nuclear Research) was very interested in hypertext and wanted to create a way for researchers to share their work. - by the end of 1990, he had built the first web browser, the first web server and the first simple webpages. in august 1991, CERN announced the web to the world. - After Berners-Lee's browser came others. The first windows web browser was Mosaic, developed at NCSA (nat'l center for supercomputing applications) at UIUC. - Funding came from the high performance computing act of 1991. - superceeded in 1994 by Netscape Navigator which grew to be the worlds most popular web browser - Microsoft Internet Explorer [1.4] ---heterarchical (p15-16) (network of networks) - versus hierarchical - robust --> a robust network can operate if some parts are removed - dynamic routing - selected at time of transmission -- no one essential site is responsible for operation of the whole network -- computers that route data across the internet are called routers [1.5] - IP addresses -- every computer connected to the internet has one - computers on the internet are called HOSTS or HOST MACHINES - contrast with DNS addresses (domain name service) - discuss domain names - The IP address for most host machines are mapped to a Domain Name Service (DNS) address in order to be more people-friendly The DNS address consists of a host name followed by a domain name - domain aliases - top level domain names (com, org, edu, net, mil, gov, countries) - Each domain name consists of: Institutional site name Top Level Domain name (TLD) Example: cs.umass.edu cs.umass is the Dept. of Computer Science at the University of Massachusetts at Amherst edu refers to an educational site - New TLDs have been added as the original set became overloaded (28 million domain names) - ICANN added them approved in 2000, aero biz coop info museum name pro - While each machine has a unique IP address, it can have multiple DNS addresses (called aliases) - Anyone can register a DNS address - When you type in a DNS address, a domain name server translates it into an IP address. - Your ISP has a DNS server [1.6] - When you go online, your computer exchanges data with other computers. - The transfer of data is measured in bits per second (bps); bandwidth - Your data transfer rate is determined by: The type of connection (e.g. dial-up) The traffic over the network - A 56K connection doesn't actually run that fast, closer to 40-45 kbps. - Discuss kbps = 1000 bits per second, NOT 1024 - The bottleneck is the part of your connection that slows the data rate during transfer - Your computer isn't as fast as the other ones, data moves only as fast as the slowest link [1.7] CLIENTS & SERVERS - Clients and servers are host machines - CLIENT = information consumer, SERVER = information producer - A client is the host machine that requests information from the server - The server provides a SERVICE, like serving web pages, or handling instant messages, or streaming music or video. - server just waits around until client requests something - The server is a resource that provides a service for (many) clients - The client/server interaction is the foundation for all Internet communication [1.8] WWW AND WEB BROWSERS - The World Wide Web has become a popular means of accessing information and services. - The Web and the Internet are not the same. - internet is made up of many different components, one of these is the world wide web (WWW) or just WEB - The WWW is just one method of exchanging data over the internet, a relative newcomer. - There were many others around before the WWW, all were text-based. - at first there was just text, email, FTP, telnet, gopher BROWSERS - web browser - piece of software that enables users to view information on the web - hypertext - text that contains pointers to other documents, called hyperlinks or links - was around before the internet (eg, encyclopedias on cdrom) - lets you easily weave through multiple documents according to what strikes your fancy - don't have to be related, can be on very diverse topics - each webpage on the internet has a URL (uniform resource locator) - anatomy of a URL - protocol - host - path