Textbook Notes (362,984)
Canada (158,126)
Criminology (610)
CRIM 101 (121)
Chapter 6

Chapter 6.docx

4 Pages
Unlock Document

Simon Fraser University
CRIM 101
Kamal Masri

Chapter 6  Networks and Collaboration o Collaboration – two/more people working together to achieve a common goal, result, product. o Useful because results are greater than those that could have been produced by a single individual. o Effectiveness driven by (order of importance varies from job to job)  Communication skills/culture  Most important factor  Ability to be part of a group  Giving/receiving feedback  Easiness felt by employees in group to contribute without being criticized in a way that creates resentment instead of improvement  Communication Systems  Availability of email, VPN, IM, other electronic communication systems allow meetings from people of conflicting geological locations and time schedules  Content Management  Users must manage content so that conflicting data changes do not happen “lost update”  Information systems and database management systems must ensure appropriate amount of permissions and privileges/rights are given out to appropriate users  Workflow control  A process/procedure by which content is created, edited, used, and disposed  While business process focuses on delivering external goods/services to customer, workflow focuses on delivering goods/service internally to other employees in organization. o Ex: specify who creates a website  who then reviews it  Specifies order of tasks and processes for handling rejected changes as well as exceptions  Network Externalities o Network externalities – more people in a network = more valuable the network is o Critical mass – when value of being part of the network is larger than cost of being on it  Following critical mass, networks will grow faster o Network growth is limited because of congestion, market becomes saturated growth diminishes/becomes negative What is a computer network? Network – collection of computers that transmit and/or receive electronic signals through transmission media o Transmission media – physical media, copper cables, optical fibre cable, wireless media transmitting light/radio frequencies (including cellular and satellite systems)  3 basic types of networks o Local area network (LAN) –  Connects computers within a relatively small, single geographic location  2 to several hundred of connections o Wide Area Networks (WANs) –  More than one geographic location o Internets  Network of networks  Connects LANs, WANs, other internets  Protocol – set of rules that two communicating devices follow o Different protocols for LANs, WANs, and for Internet o Device on same LAN must have same protocol What are the components of a LAN?  Network in a single location (within 1 km)  All computers are on company’s property and controlled by that company  Switch – special-purpose computer that receives and transmits messages on the LAN o Ie. Computer 1 sending print job to switch, then switch redirecting data to printer to print out o LANs may have more than one switch, example: a switch on each floor which responds to a main switch  Network interface card (NIC) – connects device circuitry to network cable and implements protocols necessary for communication  Media access control address (MAC) – unique identifier of the NIC o Devices are connected using either  Unshielded twisted pair (UTP) – most common connection type  4 cables twisted together to reduce cross-write signal interference  UTP cable is connected into NIC by using a RJ-45 connector  Optical fibre cables o Replace UTP cables when a lot of traffic/far distances come into play o Signals are light rays which are reflected inside glass core of the optical fibre cable o Cladding surrounds core to contain light signals o Two common optical connectors: ST & SC  The IEEE 802.3/Ethernet/Protocol o IEEE is the sponsor of committees that create/publish protocols o IEEE 802.3 protocol or Ethernet  Most popular protocol standard  Specifies hardware characteristics, such as what wire carries what signals and describes how message are to be packaged and processes for LAN transmission o 10/100/100 Ethernet – onboard NIC on personal computers that allow transmission rate of 10,100,1000 Mbps  Speed detected then communicated with by switch o K = 1000 for transmission speeds, not 1024 like for memory  Expressed in bits not bytes  Wireless LANs o Computer network that allows users to connect to a network without using network cables o WNIC = wireless NIC, allows wireless connection o Wifi also called 802.11(letter of speed) or wireless LANs o Access points (AP) – 1/more required for wireless LAN, allows devices to connect  Can range from 40-100 meters  Outdoor has longer range, depends on weather, obstructions, similar frequency interference, reflectors and repeaters o If connected to both 802.11 (wireless) and 802.3 (cable connection), AP must process according to BOTH What Do I Need to Know about Connecting to the Internet?  Router – special purpose computers that implement protocol for WANs and allows device access to internet by connecting device to computers owned/operated by ISP  ISP’s 3 main functions o Provides computers/router with legitimate Internet address o Acts as gateway to Internet by receiving communications from internet then passing to router then passing to computer o Help pay for internet by collecting money from customers  Browsers – programs that implement HTTP, FTP, SMTP protocols o HTTP – hypertext transfer protocol  Automatically filled in by browser to indicate it will use HTTP to communicate with webpage o FTP – file transfer protocol  Transferring of files between computers on the Internet o SMTP – simple mail transfer protocol  PG 182 diagram  Names and Addresses o Top level domain (TLD)  Ie. “.ca” “.com”  Governed by Internet Corporation for Assigned Names and Numbers, TLDs leased to agencies o Uniform resource locator (URL) – a name for a website, instead of typing in an IP address (logical address) o Ex. www.canada.ca =  Obtaining an IP Address o Public IP – used on internet, assigned to ISPs & major institutions in blocks by ICANN, each IP is unique for computers on internet o Private IP – used within private networks, controlled only by computers that operates the private network o Plug computer into LAN/connect to WiFi  program in OS will find Dynamic Host Configuration Protocol (DHCP) on network  computer requests and given temporary IP by DHCP server  once disconnected, IP is available again and reassignable  Finding Domain Names o DNS – convert human friendly URLs (names) into computer friendly IPs (numbers)  Process of this conversion is called domain name resolution  Done by domain name resolvers that reside at ISPs, schools, large companies, government
More Less

Related notes for CRIM 101

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.