The Internet and its uses

The Internet is a worldwide, publicy accesible network of networks.
A standard is a set of rules that determines how something must be done

• networking and Internet standards ensure that all devices connecting to the network use the same set of rules.
• there are thousands of Internet standards that help define the rules for how devices are communicating on networks.

Internet service provider- a company or organization through which a subscriber obtains Internet access
Services porvided by the ISP:
a.) Equipment co-location
            -  a bussiness can opt to have some or all internal network equipment physically located on the ISP  premises
b.) Web hosting
            – the ISP provides the server and application software for storing web pages
c.) FTP
            – servers and application software for the FTP site of a bussiness
d.) Application and media hosting
            – provides streaming media such as music, video or applications such as databases
e.) Voice over IP
f.) Technical support
            - consulting services
g.) Point of presence (POP)
Internet Service Providers:

• Dial up – inexpensive
               – uses phone lines and a modem
               – slowest connection option
  
• DSL – more expensive than dial up
           - faster connection
           – uses a special high speed modem that separates the DSL signal from the telephone signal
  
• Cable modem – offered by cable television service providers
                           – uses a special modem
  
• Satellite – offered by satellite service providers
                 – the users connect through a satelitte

Bandwidth is measured in bits per second.Three main types of high-bandwidth connection:
1.) T1 connection - transmit data up to 1.544 Mbps
                               – is symetrical
                               – a medium-sized bussiness may need only one T1 connection
2.) T2 connection – transmit data up to 45 Mbps
                               - more expensive than T1
                               – larger bussiness may need a T3 connection
3.) Metro Ethernet – offers a wide range of high bandwidth, including Gbps links
                                  - large companies uses Metro Ethernet, such as banks, etc.
                                  – allows the transfer of larger amounts of data faster and less expensively than other high-bandwidth connection
IXP or NAP – where multiple ISPs join together to gain access to each others `s networks and exchange information
                      – there are currently over 100 major exchange points located worldwide.
                      – IXP = Internet Exchange Point
                      – NAP = Network Access Point
Internet backbone – group of networks ownedby varios organization and interconnected through IXPs and private peering connections.The primary medium used is fiber optic cable.
ISPs are classified into different tiers:

• Tier 1 – huge organizations that connects directly with each other through private peering
              – own the routers, the high speed data links and other equipment (undersea cables that connects the continents)
  
• Tier 2 – can also be very large, even extending across several countries
             - pay Tier1 for access to the internet
  
• Tier 3 – the farthest away from the backbone
              – generally found in many cities
              – provides customer local access to the global internet

Scalability- the capacity of a network to allow for future change and growth
Network support services: – planning and provisioning of new equipment
                                                – adding new subscribers
                                                - network repair and maintenance
                                                – customer service for network connectivity issues
Roles and responsabilities: – customer service
                                               - planning and provisioning
                                               – on-site installation
                                               – Network Operation Center(NOC)
                                               – Help desk