INTRODUCTION TO COMPUTER NETWORKS Flashcards
What is a computer network?
A connection of two or more computers for the purpose of communication of information and the sharing of resources.
What is a bit?
Protocol Data Units in the lower physical layer
What are protocols?
Rules that govern data communication eg STMP and FTP
What is media?
channels over which messages travel in a network eg wired or wireless
What are packets?
Pieces of a message in the network layer
What is a PDU?
Protocol Data Unit- Data in a network eg bits and packets
What is a topology?
Network lay-out or plan. Could be physical (eg star bus etc) or logical (in terms of configuration)
Define configuration
Process of assigning network settings, policies, flows and controls. (Basically the arrangement of the elements of the network)
Define downtime
A state whereby the network is functioning below baseline settings (optimum expectation)
What is SLA?
Service-level-agreement- An agreement between a service provider and a client. Eg Facebook and its clients
What is uptime?
State whereby the network is functioning above optimum expectation
What is a domain?
An administrative grouping of multiple private computer networks or local hosts within the same infrastructure. It defines entities eg .co.ke is a company in Kenya and how networks are configured eg collision domain
What are addresses?
Unique identifiers in a network eg IP, MAC, Port number etc.
What are the qualities of a network?
- Maintainability- Failed components should be restored to a particular condition within a specified period.
- Manageability- Should be easy to control.
- Scalability- Ability of a network to expand or scale down as per an organizations requirements
- Security- Data in a network should be secure and safe from CIA violations.
- Fault tolerance- The network should continue operating despite of failures and malfunctions of components
- Quality of Service (Qos)- Refers to any technology that manages data traffic to reduce packet loss, latency and jitter on a network
Describe the CIA Triad
- Confidentiality. Your data should be visible and accessible only to those whom you choose to see it.
- Integrity. The data you see and store should be reliable and accurate, and should not be tampered with. You need to be able to trust this data.
- Availability. Your data should be accessible when you want it, including after a mishap or disaster.
What are the advantages of networking?
- Increases Connectivity and Communication
- Allows for Data Sharing
- Allows for Hardware Sharing
- Provides Internet Access
- Internet Access Sharing
- Enhances Data Security and Management
- Performance Enhancement and Balancing
What are the disadvantages of networking?
- Network Hardware, Software and Setup Costs
- Hardware and Software Management and Administration Costs
- Undesirable Sharing eg in certain topologies
- Illegal or Undesirable Behavior eg hacking
- Data Security Concerns
What are the functions of a network?
- Communication – Through platforms such as email, mobile, chat, social media
- Decision making – Networks in information systems are a source of data which greatly influences decision making.
- Monitors –surveillance, time logging, illegal activities.
- Security – forensics –Government
- Resource sharing – network printer, files etc
- System auditing
Differentiate between a node and a host
A network node is any device participating in a network. A host is a node that participates in user applications, either as a server, client, or both. A server is a type of host that offers resources to the other hosts.
What is a host
All computers that are connected to a network and participate directly in network communication are classified as hosts. Hosts can be called end devices. Some hosts are also called clients. However, the term hosts specifically refers to devices on the network that are assigned a number (IP address) for communication purposes.
What is a client?
Clients are a type of host. Clients have software for requesting and displaying the information obtained from the server. An example of client software is a web browser, like Chrome or FireFox. A single computer can also run multiple types of client software.
What is a server?
Servers are computers with software that allow them to provide information, like email or web pages, to other end devices on the network. Each service requires separate server software. For example, a server requires web server software in order to provide web services to the network.
Give examples of server software
- The email server runs email server software. Clients use mail client software, such as Microsoft Outlook, to access email on the server.
- The web server runs web server software. Clients use browser software, such as Windows Internet Explorer, to access web pages on the server.
- The file server stores corporate and user files in a central location. The client devices access these files with client software such as the Windows File Explorer.
Give examples of intermediary devices
Wireless Router, LAN Switch, Router, Multilayer switch, Firewall appliance
