Transcript Networks and the Internet

COMM 226
Networks and collaboration
Chitu Okoli
Associate Professor in Business Technology Management
John Molson School of Business, Concordia University, Montréal
1
Major Network Types
• Local Area Network (LAN)
– Network in premises 100% owned by one organization
– No need to ask the city or anyone else for special permits for
laying cables
• Wide Area Network (WAN)
– Spans spaces not fully controlled by the organization (e.g.
neighborhood, city, country)
– Requires public network services
– Crosses city streets
• Internet
– International network of interconnected networks
– Owned by no one; shared by everyone
Local Area Network (LAN)
Major kinds of network cables
• Unshielded twisted pair (UTP) cable
–
–
–
–
Used for small LANs
Conducts electricity using copper cables
Similar to a telephone cable, but thicker
Maximum speed: 10 gigabits per second (1.25 GB/s)
• Fibre optic cable
–
–
–
–
Used for larger LANs and for WANs
Conducts light (lasers) within glass or plastic fibres
This is what Bell’s Fibe service uses
Maximum speed: unknown
• Current record is around
255 terabits per second
(31,800 GB/s)
Source:
https://www.google.ca/search?q=fibre+optic+speed+record&tbs=qdr:y
Comparative network transmission speeds
Local Area Network with Wireless
https://www.youtube.com/watch?v=okeSqr5eOmU
Basic Internet connection
https://www.youtube.com/watch?v=7_LPdttKXPc
URLs and domain names
http://www.concordia.ca/jmsb.html
Indicates that
this is a
webpage
(hypertext
transfer
protocol)
third-level
domain
(optional)
second-level
domain
(acquired by
organizations
or individuals)
top-level filename of
domain
HTML
(assigned document
by ICANN)
html or htm
extension
(optional)
• Uniform Resource Locator (URL)
– easy to remember address on the Internet
• Domain name
– Unique name to identify a node on the Internet
– Corresponds to an IP address (132.205.244.70)
• http://ip-lookup.net/domain.php
– Domain Name Service (DNS) maps domain names to
their corresponding IP address
• Like how a phone book maps people’s names to their
corresponding phone numbers
– Contains sub-domains, separated by periods
Common top level domains (TLDs)
Domain
Description
com, net, org, info
Anyone, anywhere
edu
Higher education
gov
United States Government
mil
United States Military
ca, uk, us, mx, fr
Country indicators
tv, fm, co, md, cc, ws
Country indicators with special marketing
biz, name, care, etc.
Newer TLDs with particular meanings
9
Virtual Private Network (VPN)
https://youtu.be/rFg7TSwVcL4
Virtual Private Network (VPN)
• Private network: like your home network or enterprise
network—it is private, not public like the Internet
• VPN uses the Internet to create a special connection with
the security and privacy of private network (hence, a
“virtual” private network)
• VPN advantages:
– Secure, encrypted connection (harder to hack or spy)
– Access to special resources normally available only to the private
network
• VPN disadvantages:
– Slower connection because of encryption
– Sometimes somewhat complicated to set up
• Concordia provides free VPN
Sources
• Most of the slides are adapted from COMM 226
Business Technology Management by David M.
Kroenke, Andrew Gemino, Peter Tingling, and Earl H.
McKinney, Jr. 2nd Custom Edition for Concordia
University (2014) published by Pearson Canada.
ISBN 13: 978-1-269-96956-7
• Other sources are noted on the slides themselves
12