HYPOTHESIS ACTIVITY Question and Hypothesis Worksheet A student is interested in designing several experiments to test the factors that effect how qui … Show how to attract a paper to a comb without using glue? find the mass of an object with acceleration of 100m/s and has a force of 100N. a cart has a mass of 20kg and accelerate at 2m/s²,what is it's next external force? Direction: Convert the following values to their designated form. 1. 55 kilograms 2. 12.5 centimeters 3. 25 centimeter³ 4. 2260 seconds 5. 490 minutes … anong pwedeng I answer sa for cleaning and for cooking and for eating and for gardening Homogeneous. Heterogeneous 1 1 2. 2 3. 3 4. … list 6 minor listhospheric 1. What is the magnitude of the centripetal force that must be applied in order for a 0.50 kg ball on a 2.0 m string to spin with uniform circular mot … please help my assignment in science 7
LANs, WANs, and the Internet (1.3)Most web users never consider how the Internet works. In this section you will begin to explore the pieces that come together to enable network communications. Components of a Network (1.3.1)In this section you will begin to learn about the devices and equipment that work together in networks. Components of the Network (1.3.1.1)The path that a message takes from source to destination can be as simple as a single cable connecting one computer to another or as complex as a network that literally spans the globe. This network infrastructure is the platform that supports the network. It provides the stable and reliable channel over which our communications can occur. The network infrastructure contains three categories of network components:
Devices and media are the physical elements, or hardware, of the network. Hardware comprises the components of the network platform that typically are visible, such as a laptop, PC, switch, router, wireless access point, or the cabling used to connect the devices. Occasionally, some network components may not be visible. In the case of wireless media, for example, messages are transmitted through the air using invisible radio frequency or infrared waves. Network components are used to provide services and processes. These services and processes are the communication programs, called software, that run on the networked devices. A network service provides information in response to a request. Services include many of the common network applications people use every day, like email hosting services and web hosting services. Processes provide the functionality that directs and moves the messages through the network. Processes are less obvious to us but are critical to the operation of networks. End Devices (1.3.1.2)The network devices that people are most familiar with are called end devices, or hosts. These devices form the interface between users and the underlying communication network. Some examples of end devices are
A host device is either the source or destination of a message transmitted over the network. In order to distinguish one host from another, each host on a network is identified by an address. When a host initiates communication, it uses the address of the destination host to specify where the message should be sent. In modern networks, a host can act as a client, a server, or both. Software installed on the host determines which role it plays on the network. Servers are hosts that have software installed that enables them to provide information and services, like email or web pages, to other hosts on the network. Clients are hosts that have software installed that enables them to request and display the information obtained from the server. Intermediary Devices (1.3.1.3)Intermediary devices interconnect end devices. These devices provide connectivity and work behind the scenes to ensure that data flows across the network. Intermediary devices connect the individual hosts to the network and can connect multiple individual networks to form an internetwork. Examples of intermediary network devices are
The management of data as it flows through the network is also a role of the intermediary devices. These devices use the destination host address, in conjunction with information about the network interconnections, to determine the path that messages should take through the network. Processes running on the intermediary network devices perform these functions:
Network Media (1.3.1.4)Communication across a network is carried on a medium. The medium provides the channel over which the message travels from source to destination. Modern networks primarily use the following three types of media to interconnect devices and to provide the pathway over which data can be transmitted:
Figure 1-12 shows examples of the three types of physical media. The signal encoding that must occur for the message to be transmitted is different for each media type. On metallic wires, the data is encoded into electrical impulses that match specific patterns. Fiber-optic transmissions rely on pulses of light, within either infrared or visible light ranges. In wireless transmission, patterns of electromagnetic waves depict the various bit values. Different types of network media have different features and benefits. Not all network media types have the same characteristics or are appropriate for the same purpose. The criteria for choosing network media are
Network Representations (1.3.1.5)When conveying complex information, such as displaying all the devices and media in a large internetwork, it is helpful to use visual representations. A diagram provides an easy way to understand the way the devices in a large network are connected. Such a diagram uses symbols to represent the different devices and connections that make up a network. This type of “picture” of a network is known as a topology diagram. Like any other language, the language of networking uses a common set of symbols to represent the different end devices, network devices, and media, as shown in Figure 1-13. The ability to recognize the logical representations of the physical networking components is critical to being able to visualize the organization and operation of a network. Throughout this course and its accompanying labs, you will learn both how these devices operate and how to perform basic configuration tasks on these devices. In addition to being able to recognize these representations, you need to understand the specialized terminology that is used when discussing how each of these devices and media connect to each other. Important terms to remember are
Topology Diagrams (1.3.1.6)Topology diagrams are mandatory for anyone working with a network. A topology diagram provides a visual map of how the network is connected. There are two types of topology diagrams:
LANs and WANs (1.3.2)This section explains how LANs and WANs form computer networks. Types of Networks (1.3.2.1)Network infrastructures can vary greatly in terms of
Figure 1-15 illustrates the two most common types of network infrastructures:
Other types of networks include
Local-Area Networks (1.3.2.2)LANs are a network infrastructure that spans a small geographical area. Specific features of LANs include
Wide-Area Networks (1.3.2.3)WANs are a network infrastructure that spans a wide geographical area. WANs are typically managed by service providers (SPs) or Internet service providers (ISPs). Specific features of WANs include
The Internet (1.3.3)This section explains how the Internet consists of many connected LANs and WANs. The Internet (1.3.3.1)Although there are benefits to using a LAN or WAN, most individuals need to communicate with a resource on another network, outside of the local network within the home, campus, or organization. This is done using the Internet. As shown in Figure 1-16, the Internet is a worldwide collection of interconnected networks (internetworks or the Internet for short), cooperating with each other to exchange information using common standards. Through telephone wires, fiber-optic cables, wireless transmissions, and satellite links, Internet users can exchange information in a variety of forms. The Internet is a conglomerate of networks and is not actually owned by any individual or group. Ensuring effective communication across this diverse infrastructure requires the application of consistent and commonly recognized technologies and standards as well as the cooperation of many network administration agencies. There are organizations that have been developed for the purpose of helping to maintain structure and standardization of Internet protocols and processes. These organizations include the Internet Engineering Task Force (IETF), Internet Corporation for Assigned Names and Numbers (ICANN), and the Internet Architecture Board (IAB), plus many others. Intranet and Extranet (1.3.3.2)Two other terms are similar to the term Internet: Intranet is a term often used to refer to a private connection of LANs and WANs that belongs to an organization, and is designed to be accessible only by the organization’s members, employees, or others who have authorization. An intranet is basically an internet that is usually only accessible from within the organization. An organization may publish on its intranet web pages about internal events, health and safety policies, staff newsletters, and staff phone directories. For example, a school may have an intranet that includes class schedule information, online curriculum, and discussion forums. Intranets usually help eliminate paperwork and speed up workflows. An organization’s intranet may be accessible to staff working outside of the organization by using secure connections to the internal network. An organization may use an extranet to provide secure and safe access to individuals who work for different organizations but require company data. Examples of extranets include
Connecting to the Internet (1.3.4)This section explores the different ways to access the Internet. Internet Access Technologies (1.3.4.1)There are many different ways to connect users and organizations to the Internet. Home users, teleworkers (remote workers), and small offices typically require a connection to an Internet service provider (ISP) to access the Internet. Connection options vary greatly depending on the ISP and the geographical location. However, popular choices include broadband cable, broadband digital subscriber line (DSL), wireless WANs, and mobile services. Organizations typically require access to other corporate sites and the Internet. Fast connections are required to support business services, including IP phones, video conferencing, and data center storage. Business-class interconnections are usually provided by service providers (SPs). Popular business-class services include business DSL, leased lines, and Metro Ethernet. Connecting Remote Users to the Internet (1.3.4.2)Figure 1-17 illustrates common Internet connection options for small office and home office users, which include
Many homes and small offices are more commonly being connected directly with fiber-optic cables. This enables an ISP to provide higher bandwidth speeds and support more services such as Internet, phone, and TV. The choice of connection varies depending on geographical location and service provider availability. What are your options for connecting to the Internet? Connecting Businesses to the Internet (1.3.4.3)Corporate connection options differ from home-user options. Businesses may require higher bandwidth, dedicated bandwidth, and managed services. Connection options available differ depending on the number of service providers located nearby. Common connection options for organizations include
The choice of connection varies depending on geographical location and service provider availability. Most Powerline kits provide two adapters, each with an Ethernet port. One device connects to an electrical outlet and tethers to a modem or router's LAN port using an Ethernet cable. The second unit plugs into another electrical outlet near the device you want connecting to the network. Network Interface Card – A NIC, or LAN adapter, provides the physical connection to the network at the PC or other end device. Explanation: Video communications is a good conferencing tool to use with others who are located elsewhere in your city, or even in another country. Any electronic device on a network is called a Node. In telecommunications networks, a node is either a redistribution point or a communication endpoint. ... |