Transcript internet overview lecture slides

SOCIAL WEB MEDIA
Course Introduction
and
Technical/Conceptual Foundations
lecture based on:
Navigating the Internet - Smith, Gibbs, McFedries
Pocket Guides to the Internet – Veljkov
Protocol (ch 1) – Galloway
Wikipedia entries
BASIC TERMS
BASIC TERMS
INTERNET
WORLD WIDE WEB
PROTOCOL
TCP/IP
IP ADDRESS
DNS
INTERNET
or
WEB?
The Internet is a worldwide, publicly accessible series of
interconnected computer networks that transmit data by packet
switching using the standard Internet Protocol (IP) (Wikipedia)
“A worldwide network of networks” (Veljkov p1)
The World Wide Web (WWW)
...a system of interlinked hypertext documents accessed via the
Internet. (Wikipedia)
Email ?
instant messaging ?
(IRC, Jabber, etc)
Facebook chat ?
Usenet ?
PROTOCOL
general definition
“agreed-upon methods of communication used by
computers and, for that matter,
by people.” (Smith p6)
CULTURAL PROTOCOLS
telephone call protocol
bank line protocol
grocery store line protocol
classroom protocol
In a formal meeting...
“someone chairs the meeting, states its objectives... invites people
to speak. When each person finishes speaking, control returns to
the chair.”
ways for handling
interjections
error conditions
(Smith p6)
for networked computers...
which computer begins communication
how replies are handled
how will data be represented
how will errors be handled
TCP/IP
two protocols...
Transmission Control Protocol
Internet Protocol
protocol suites or protocol stacks
lowest level to highest level
lowest level: basic functions...
receiving pulses of electricity from the
communications medium
Application layer
Transport layer
Internet layer
Link layer
Application layer
(content)
Transport layer
(makes sure data arrives correctly – a social layer)
Internet layer
(actual movement of data from one place to another)
Link layer
(hardware-specific)
Application layer
(content)
Telnet, FTP, HTTP
Transport layer
(makes sure data arrives correctly – a social layer)
TCP, UDP
Internet layer
(actual movement of data from one place to another)
IP & ICMP
Link layer
(hardware-specific)
Compare to telephone call “protocols”
conversation – (application layer)
“Are you still there?” - (transport layer)
“Can you repeat that?” - (transport layer)
“Hi, this is...” “OK – Bye!” (transport layer - establishing
and closing the connection)
phone switching/routing (analogous to Internet layer)
physical phone or fiber optic lines (link layer/hardware
layer)
Internet Protocol
Developed to enable different local area networks to
communicate with each other
Has become the basis for connecting computers
around the world together over the Internet
TCP/IP
IP = breaking up data and sending it
TCP = make sure data arrives intact
error correction is the responsibility of TCP
routing is the responsibility of IP
Data
Transmission consists of sending/receiving streams of
zeros and ones along the network connection
Two
Types of Information:
Application data
The information one computer attempts to send to another
Network protocol data
Describes how to reach the intended computer
Describes how to check for errors in the transmission
Data
must be marked with a destination address
IP ADDRESS
In IP the destination address is 4 bytes
(each byte is a number 0-255)
example:
64.233.167.104
http://64.233.167.104/
To be able to accommodate more devices, IP
addresses will be extended to sixteen bytes
DNS
Domain Name System
resolves names “www.rhizome.org”
into IP addresses
206.252.131.211
When
a computer wants to request data from a domain
name:
It asks the DNS for the numeric Internet Address
It includes the numeric address with the request for data
Domain Name Servers
distributed
Domain Name System
inverted tree structure
decentralized hierarchy
. (root)
_____________|__________
|
|
|
|
.org
.com .net
.edu
|
|
google
buffalo
|
|
|
images
www mediastudy
to resolve the numerical address for mediastudy.buffalo.edu first a
request goes to a root nameserver to find out where the appropriate top
level domain server (.edu) is, then that server is queried as to where the
host (buffalo) is, then the host is queried for the address of the actual
computer in question (mediastudy)
Each server only has info about
the area directly below it in the
hierarchy.
Decentralized network model.
Protocols
TCP/IP
peer-to-peer
non-hierarchical
distributed
DNS
hierarchical
decentralized
FLOW
IP
breaks large chunks of data up into more manageable
packets
Each
packet is delivered separately
Each
packet in a larger transmission may be sent by a different
route
Packets
The
are numbered
recipient reassembles the data
Internet
Protocol (IP) does not notify the sender if data is lost or
garbled
This
is the job of a higher level protocol Transmission Control
Protocol (TCP)
The
most commonly used Internet services use TCP with IP
(TCP/IP)
Attempt
Try
to deliver the data
again if there are failures
Notify
the sender whether or not the attempt was successful
PART 2:
“The emergence of distributed networks is
part of a larger shift in social life. [...] a
movement away from central bureaucracies
and vertical hierarchies toward a broad
network of autonomous social actors.”
- Galloway
PART 2:
“The emergence of distributed networks is
part of a larger shift in social life. [...] a
movement away from central bureaucracies
and vertical hierarchies toward a broad
network of autonomous social actors.”
- Galloway
PART 2:
NETWORK TOPOLOGIES
CENTRALIZED
DECENTRALIZED
DISTRIBUTED
HUBS
NODES
HIERARCHIES
RHIZOME
[[clip: Apple Macintosh 1984 ad]]
changes in workplace
teams/outsourcing/consulting etc.
Protocol
“a set of guidelines or rules” (Wikipedia)
Uses of term protocol:
military
chain of command, hierarchy
Internet
flexible, distributed, resistive of hierarchy
Network Topologies
Network models
Centralized
Decentralized
Distributed
discuss in terms of hubs and
nodes...
Image: Rand Corporation
Cold War origins of Internet*
(*specifics are open to debate)
two images:
nuclear attack
Internet
Two images:
nuclear attack
“highly energetic, dominating, centralized”
Internet
“non-centralized, non-dominating, nonhostile”
(Galloway)
Image: Rand Corporation
centralized networks:
hierarchical
a single authoritative hub
“top-down management”
US judicial system
Bentham's Panopticon (as
discussed by Foucault)
decentralized networks:
network diagram of the modern era
multiple hubs w/ dependent nodes
airline system (airline hubs)
university departments
distributed networks:
no central hubs
no radial nodes
each entity is autonomous
Internet
freeway system
Many paths to a destination
freeway system
if 90 is closed use another route

“The emergence of distributed networks is
part of a larger shift in social life. [...] a
movement away from central bureaucracies
and vertical hierarchies toward a broad
network of autonomous social actors.”
“The emergence of distributed networks is
part of a larger shift in social life. [...] a
movement away from central bureaucracies
and vertical hierarchies toward a broad
network of autonomous social actors.”
- Galloway
Gilles Deleuze and Felix Guattari
metaphors:
arborescent
tree-like structure
directional
rhizomatic
root network (ginger)
multiple, non-hierarchical
image: Wikipedia
“What was once protocol's primary liability in its former military
context – the autonomous agent who does not listen to the chain of
command – is now its primary constituent in the civil context.”
(Galloway p38)
Classical era
sovereign
central control
Classical era
sovereign
central control
Modern era
bureaucracy
decentralized control
Classical era
sovereign
central control
Modern era
bureaucracy
decentralized control
Now
???
How it works...
materiality of the Internet
host computers
clients (receiver of information)
servers (sender of information)

Network conditions are always changing...
traffic
bandwidth
hosts going offline

Packets “hop” from host to host.
Each host only knows what
general direction
the packet is headed.
Each host knows which of its
neighboring hosts
lie in which direction.
If transmission to a neighbor fails, the host updates its information.
Each packet is given a “time-to-live” number.
Each hop subtracts from the “time-to-live.”
If the packet reaches 0 it is deleted.
Each packet has a header.
source address
destination address
checksum
Protocological characteristics of TCP/IP
facilitates peer-to-peer communication
distributed technology (meshwork/rhizome)
universal language (any 2 computers that speak TCP/IP can
network)
robust and flexible/ not rigid and tough
open to theoretically unlimited variety of computers
is a result of the action of autonomous agents (computers)
