Week 7: Internet and WWW Technologies

1. Jeff Tyson, "How Internet Infrastructure Works"
http://computer.howstuffworks.com/internet/basics/internet-infrastructure.htm

Internet: interconnected network of computers

• no "real" owner --> governance? neutrality?
• Internet Society est. 1992

computer network hierarchy

• computer : modem : ISP : network
• work : LAN : ISP : network
• POP = point of presence
• access via local # or dedicated line
• diff networks connect through NAPs (network access pts)
• various connections, various geographic locations
  
  

router

•  joining 2 networks: directs info to correct destination
• examines packets and verifies whether intended for address
• config table: priorities & rules for traffic --> best route
• protocol translation?
• protects networks from each other (see: above pt)
• avoids clogging, misrouting
•  +++ network activity, +++ influences on performance

backbone

• NSFNET (1987) T1
• T1 fiber optic, good for gen browsing
•  NSF x IBM x MCI x Merit (1988) T3

IP addresses

• protocol: specific comm w/ particular service
• IP address = unique ID
• 0.0.0.0 (default) = octets (8 pos. in binary form)
• 1 or 0: 2∧8 (256); 0-255
• octets for classes of IP addresses
• 2 sections: net and host
• net: 1st octet --> network of computer
• host (node): IDs computer; always incl. last octet
• 2 standards
• IPv4: all computers, early Internet
• IPv6: compensates for IPv4 issues
• dynamic and static
• dynamic most common (Dynamic Host Configuration Protocol)
• static: self-config

DNS

• early Internet: provide IP address of destination comp
• solution: Network Info Cener text file
• map name --> IP address
• DNS: 1983, Wisconsin
• automatic mapping (name resolution); "GPS for Internet"
• connect to DNS server 
• ex. www.pitt.edu instead of actual IP address
• conversion to IP
• recognition
• contact another server to find address
• refer to another server
• error b/c IP address invalid or nonexistent

URL

• 1st-level domain: .com, .edu, .gov, etc.
• left-most word: host name
• domain can have lots of host names, as long as unique

Servers and clients

• Server: Machines w/ services to other machines
• ex. web, email, ftp
• Client: Machines used to connect to services
• Specific purpose, specific service

Ports and HTTP

• Services avail. using numbered ports
• 1 for ea. avail. service
• Access using specific protocol
•  HTTP (hypertext transfer protocol)

2. Andrew Pace, "Dismantling Integrated Library Systems." Library Journal 129(2): 34-36. http://lj.libraryjournal.com/2004/02/ljarchives/dismantling-integrated-library-systems/

• interoperability still more myth than reality
• where interoperability is only w/in each system (and not across)
• competitive advantage:  how to maintain?
• vendors must market products
• but not necessarily "better" --> efficient economically? in use?
• legacy systems, new layers
• starting from 0 may be unproductive
• users want 1-stop search/retrieval
• implications for critical media literacy?
• potential of OSS?
• Koha only basic functionality
• verdict: vendors also need to reassess own efforts

3. Sergey Brin and Larry Page, "The genesis of Google." http://www.ted.com/talks/sergey_brin_and_larry_page_on_google

• Google --> ++ equitable access
• but digital inequality remains pressing issue
• dearth in certain locations, esp. African countries
• Montessori education of founders
• play and creativity
• 20% time = "free" time for Googlers to work on own projs
• can potentially be translated to official G proj, ex. News
• transformation into global co.
• how to work with intl colleagues?
• how to work across diff geo locations?
• ultimate search engine = AI
• related searches
• algorithms for relevance
• AdSense: tailored ads
• payment for ads, not results