Chapter 5 Telecommunications, the Internet, and Wireless Technology

broadband

broadband

connections provided by telephone and cable TV companies running at 1 to 15 million bits per second

telephone networks and computer networks

Firms in the past used two fundamentally different types of networks:

computer network

two or more connected computers

network operating system (NOS)

routes and manages communications on the network and coordinates network resources

Hubs

are very simple devices that connect network components, sending a packet of data to all other connected devices

switch

has more intelligence than a hub and can filter and forward data to a specified destination on the network

router

a communications processor used to route packets of data through different networks, ensuring that the data sent gets to the correct address

Software-defined networking (SDN)

is a new networking approach in which many of these control functions are managed by one central program, which can run on inexpensive commodity servers that are separate from the network devices themselves

a client computer and a dedicated server computer, network interfaces, a connection medium, network operating system software, and either a hub or a switch

Major components of simple network

Client/server computing

is a distributed computing model in which some of the processing power is located within small, inexpensive client computers, and resides literally on desktops, laptops, or in handheld devices

Packet switching

is a method of slicing digital messages into parcels called packets, sending the packets along different communication paths as they become available, and then reassembling the packets once they arrive at their destinations

protocol

is a set of rules and procedures governing transmission of information between two points in a network

Transmission Control Protocol/Internet Protocol (TCP/IP)

was developed during the early 1970s to support U.S. Department of Defense Advanced Research Projects Agency (DARPA) efforts to help scientists transmit data among different types of computers over long distances

Application layer, Transport layer, Internet layer, Network Interface layer

the four-layered Department of Defense reference model for TCP/IP

Application layer

enables client application programs to access the other layers and defines the protocols that applications use to exchange data. One of these application protocols is the Hypertext Transfer Protocol (HTTP), which is used to transfer Web page files.

Transport layer

responsible for providing the Application layer with communication and packet services. This layer includes TCP and other protocols.

Internet layer

responsible for addressing, routing, and packaging data packets called IP datagrams. The Internet Protocol is one of the protocols used in this layer.

Network Interface layer

responsible for placing packets on and receiving them from the network medium, which could be any networking technology

analog signal or a digital signal

two ways to communicate a message in a network

analog signal

represented by a continuous waveform that passes through a communications medium and has been used for voice communication

digital signal

a discrete, binary waveform, rather than a continuous waveform

Modem

stands for modulator-demodulator. Translates digital signals into analog form(vice versa)

Local Area Networks, Wide Area Networks, Metropolitan Area Networks, Campus Area Networks

TYPES OF NETWORKS

local area network (LAN)

designed to connect personal computers and other digital devices within a half-mile or 500-meter radius

Local area network (LAN)

AREA: Up to 500 meters (half a mile); an office or floor of a building

Campus area network (CAN)

AREA: Up to 1,000 meters (a mile); a college campus or corporate facility

Metropolitan area network (MAN)

AREA: A city or metropolitan area

Wide area network (WAN)

AREA: A transcontinental or global area

Wide area networks (WANs)

span broad geographical distances—entire regions, states, continents, or the entire globe. The most universal and powerful WAN is the Internet

A metropolitan area network (MAN)

is a network that spans a metropolitan area, usually a city and its major suburbs. Its geographic scope falls between a WAN and a LAN.

bandwidth

The range of frequencies that can be accommodated on a particular telecommunications channel

hertz

The number of cycles per second that can be sent through that medium is measured

Internet

world's most extensive, public communication system that now rivals the global telephone system in reach and range. It's also the world's largest implementation of client/server computing and internetworking, linking millions of individual networks all over the world.

Internet service provider (ISP)

a commercial organization with a permanent connection to the Internet that sells temporary connections to retail subscribers

Digital subscriber line (DSL)

operate over existing telephone lines to carry voice, data, and video at transmission rates ranging from 385 Kbps all the way up to 40 Mbps, depending on usage patterns and distance

Cable Internet connections

provided by cable television vendors use digital cable coaxial lines to deliver high-speed Internet access to homes and businesses.

T1 and T3

international telephone standards for digital communication

T1 lines

offer guaranteed delivery at 1.54 Mbps, and T3 lines offer delivery at 45 Mbps

Internet Protocol (IP) address

currently is a 32-bit number represented by four strings of numbers ranging from 0 to 255 separated by periods. For instance, the IP address of www.microsoft.com is 207.46.250.119.

Domain Name System (DNS)

converts domain names to IP addresses

domain name

is the English-like name that corresponds to the unique 32-bit numeric IP address for each computer connected to the Internet. DNS servers maintain a database containing IP addresses mapped to their corresponding domain names

network service providers

trunk lines are typically owned by long-distance telephone companies

Internet Architecture Board (IAB), Internet Corporation for Assigned Names and Numbers (ICANN), and World Wide Web Consortium (W3C)

professional organizations and government bodies that established internet standard

IPv6

The old addressing system is being replaced by a new version of the IP addressing schema

Internet2

an advanced networking consortium representing over 350 U.S. universities, private businesses, and government agencies working with 66,000 institutions across the United States and international networking partners from more than 50 countries

E-mail

enables messages to be exchanged from computer to computer, with capabilities for routing messages to multiple recipients, forwarding messages, and attaching text documents or multimedia files to messages

chat

instant messaging tools that enables two or more people who are simultaneously connected to the Internet to hold live, interactive conversations

Instant messaging

type of chat service that enables participants to create their own private chat channels

Voice over IP (VoIP)

delivers voice information in digital form using packet switching, avoiding the tolls charged by local and long-distance telephone networks

Unified communications

integrates disparate channels for voice communications, data communications, instant messaging, e-mail, and electronic conferencing into a single experience where users can seamlessly switch back and forth between different communication modes.

virtual private network (VPN)

a secure, encrypted, private network that has been configured within a public network to take advantage of the economies of scale and management facilities of large networks, such as the Internet

Web site

a collection of Web pages linked to a home page

Hypertext Transfer Protocol (HTTP)

the communications standard used to transfer pages on the Web

uniform resource locator (URL)

The directory path and document name are two more pieces of information within the Web address that help the browser track down the requested page. Together, the address is called?

Hypertext Markup Language (HTML)

formats documents and incorporates dynamic links to other documents and pictures stored in the same or remote computers

Search engines

attempt to solve the problem of finding useful information on the Web nearly instantly, and, arguably, they are the "killer app" of the Internet era

Web 3.0

Web where all this digital information, all these contacts, can be woven together into a single meaningful experience

3G networks

with transmission speeds ranging from 144 Kbps for mobile users in, say, a car, to more than 2 Mbps for stationary users, offer fair transmission speeds for e-mail, browsing the Web, and online shopping, but are too slow for videos

4G network

also called Long Term Evolution (LTE) networks, have much higher speeds: 100 megabits/second download, and 50 megabits upload speed

Bluetooth

the popular name for the 802.15 wireless networking standard, which is useful for creating small personal area networks (PANs)

Wi-Fi

set of standards for wireless LANs and wireless Internet access

Hotspots

typically consist of one or more access points providing wireless Internet access in a public place.

WiMax

stands for Worldwide Interoperability for Microwave Access, is the popular term for IEEE Standard 802.16. It has a wireless access range of up to 31 miles and transmission speed of up to 75 Mbps.

Radio frequency identification (RFID)

provide a powerful technology for tracking the movement of goods throughout the supply chain

Wireless sensor networks (WSNs)

networks of interconnected wireless devices that are embedded into the physical environment to provide measurements of many points over large spaces.