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Examination Question Formats

• Malawi National Examinations have different question formats for MSCE and JCE levels.
• The questions are distributed across lower, medium, and high cognitive levels.
• MSCE level questions focus on knowledge, comprehension, application, analysis, synthesis, and evaluation, depending on the cognitive level.
• JCE level questions also cover knowledge, comprehension, application, analysis, synthesis, and evaluation.
• The distribution percentages are the following:
• MSCE:
  • Lower Level: 15%
  • Medium Level: 60%
  • High Level: 25%
• JCE:
  • Lower Level: 45%
  • Medium Level: 30%
  • High Level: 25%

Introduction to Networks

• A computer network facilitates communication between computer systems.
• Protocols are standards that govern how devices in a computer network communicate.
• Common types of computer networks include LANs, MANs, and WANs.
• A Personal Area Network (PAN) provides network capabilities in a limited area, such as connecting a computer to its accessories.
• PAN examples include devices connecting via Bluetooth.
• Local Area Networks (LANs) cover a small geographical area like an office.
• Wireless Local Area Networks (WLANs) differ by using wireless connections instead of physical cables.
• A Metropolitan Area Network (MAN) is designed to support a larger area than a LAN such as a city.
• A Wide Area Network (WAN) spans an extensive geographical area that may include states, countries, or continents.
• The primary function of a WAN is to connect devices across very large distances.
• The characteristic that varies types of networks is coverage range.
• LANs are typically more secure compared to MANs and WANs.
• One example of LAN use is sharing resources in a small office.
• Computers in a WAN are connected through various communication links.
• LANs are typically less expensive than MANs and WANs.
• Network topology refers to the arrangement of network elements.
• Two main forms of network topology are physical and logical.
• Physical topology refers to the actual layout of the network's cables and devices.
• Peripheral devices in a network include items such as printers, scanners, and external storage.
• Logical topology is the way that signals act on the network media, or the way that the data passes through the network from one device to the next irrespective of the physical interconnection of devices.
• Common physical network topologies include star, bus, ring, and mesh.
• Data in a star topology is transmitted through a central hub or switch to reach its destination.
• The function of hubs or switches is to direct to the correct destination.
• Extended star topology is characterized by multiple star networks connected together.
• Advantages of star include centralized management and fault isolation.
• The term "bus topology" describes a network where all devices are connected to a central cable (bus).
• Bus advantages are simplicity and low cost.
• Ring disadvantages: failure of one node can affect the entire network.
• Mesh topology connects each device to many other devices.
• Factors like cost, scalability, and purpose should be considered when selecting a network topology.
• The primary difference between physical and logical is the physical is the devices, logical is how it acts.
• Examples of Logical topologies is Ethernet.
• Carrier Sense Multiple Access/Collision Detection (CSMA/CD) is used in Ethernet to avoid collisions when transmitting data.
• Fast Ethernet differs from traditional Ethernet in transmission speed.
• The advantage of LocalTalk in Apple is its ease of use.
• Token Ring networks regulate traffic by passing a token between nodes.
• Redundancy in the Fibre Distributed Data Interface (FDDI) topology is significant for fault tolerance.
• Asynchronous Transfer Mode (ATM) differs by using fixed-size packets.
• Gigabit Ethernet supports higher transmission speeds and uses different types of cables.
• Ethernet and Token Ring networks differ in signal transfer and handling methods.
• Network Reference Models standardize network communication.

OSI model and TCP/IP protocol suite

• The OSI model and the TCP/IP are conceptual frameworks.
• The OSI has seven layers; the TCP/IP typically has four.
• The Physical Layer handles the transfer of data as electrical signals.
• The Data Link Layer ensures error free node to node transfer.
• The Network Layer provides logical addressing.
• The Transport Layer manages reliable end-to-end transfer of data.
• TCP guarantees delivery, UDP does not.
• The Session Layer manages sessions to coordinate communication between applications.
• The Presentation Layer ensures that data is in a usable format.
• The Application Layer interacts directly with applications to provide network services.
• The TCP/IP protocol is simpler than the OSI model.
• The Physical and Data Link Layers transmit data to and from a physical medium.
• In the TCP/IP protocol suite the Network Layer uses protocols like IP to route data packets.
• The Transport Layer includes TCP/IP protocol.
• TCP is connection oriented, whereas UDP is connectionless.
• The Application Layer includes protocols like HTTP and FTP.

Internet and Intranets

• The Internet is a global network, an Intranet is a private network contained within an organization.
• ISPs provide Internet access.
• "Internet Everywhere" and "Internet of Things" describe increased access and connectivity of devices to the internet.
• Examples of methods to access the Internet
• Dial Up
• DLS
• Cable
• A modem facilitates via telephone lines by converting digital signals.
• GSM and CDMA are mobile network types used for Internet access.
• 3G networks have specified maximum speeds.
• Subscribers can access fibre via optical fibre cables.
• WiMAX provides over long distances but requires towers and receivers.
• A Wi-Fi hotspot is a location that provides internet, and can be found in public places.
• Wi-Fi connects to the Internet wirelessly through hotspots.
• Fibre offers speed and reliability.
• WiMAX is suitable because it provides coverage over long distances.

IP Addresses

• An IP address uniquely identifies a device on a network.
• Addresses are used to specify the source and destination of data packets.
• IPv4 and IPv6 are used.
• IPv4 addressing uses 32 bits.
• IPv4 and IPv6 address sizes affect the number of unique addresses available.
• IP addressing involves assigning addresses to networks and hosts.
• Class A is for large networks.
• Class B network can accommodate a certain number of host addresses.
• Class C network can accommodate a certain number of hosts.
• IPv6 addressing involves hexadecimal and colon notation.
• IPv6 addresses use a different method specifying network and host IDs.
• IPv6 a larger address space compared to IPv4.
• IPv6 offers flexibility.
• IP addresses can be configured in the OS operating system.
• Subnet masks define the network portion.
• IPv6 addresses are represented and specified differently.
• A network number identifies the network.
• WiMAX advantages and disadvantages include range versus speed.

Network Applications

• Network applications enable communication between different devices.
• The World Wide Web (WWW) is a system for accessing information via the Internet.
• A web browser allows users to view web content.
• A Uniform Resource Locator (URL) specifies that address on the web.
• Search engines locate information on the web through various components.
• A hypertext is a document with hyperlink to other files that does not have to be linear.
• Google, Bing, and DuckDuckGo are search engines.
• A search engine retrieves relevant search results.
• A "website" is a collection of web pages.
• A web server stores and delivers content.
• Search engines create indexes by scanning web pages for keywords.
• A home page is the main or index page of a website.
• Hyperlinks enable navigation within hypertext documents.
• A "search query" is what users enter to find info.
• A web crawler discovers and indexes web content.
• The content highlights the services.
• The World Wide Web serves as a global information medium.
• Blogs are a type of website.
• Email differs by offering advanced communication.
• Email offers features like file attachments.
• Email, which uses digital, and facsimile operate differently when communicating.
• Instant messaging provides real time digital communication.
• E-commerce disadvantages include security concers.
• E-learning is online education.
• Newsgroups facilitate online discussions.
• Web browsing is the general process required to view web pages.
• A web address is the URL.
• The URL format consists of schemes // servers /path /filename .
• Hyperlinks are elements you can click on to go to another web page.
• The back button navigates through previously visited pages.
• Bookmarking saves a web link.
• Web pages can be printed through the browser's print function.
• Electronic mail require accounts to transmit digital data.
• Gmail and Yahoo are email providers.
• Standard email messages contain a header, body, and signature.
• The subject describes the email's content.
• Files can be attached and sent within emails.
• Signatures are the name at the end of emails.
• The header contains email information.
• Email addresses can be separated by periods and at symbols.
• Various types of files may be attached.
• Gmail sets a file limit for attachments.
• Contacts make it simple to add names to message.
• Social networks differ from media.
• Twitter and LinkedIn are social networks.
• Advantages of social networking are its global connections.
• Social networking can cause decreased productivity.
• The Internet can promote ideas using web connections.
• Distributed systems differ from concentrated structures.

Distributed Systems

• Distributed systems offer distributed operating systems.
• Distributed applications run across different networks using hardware management.
• Balancing load is a main distributed action.
• Databased depend on system resources.
• Security is one aspect when using multiple users.
• Comparing centralized networks shows various advantages.
• One key advantages offered by distributed systems is scalability.
• Network applications allow shared space.

Using Databases

• Databases are an important aspect of database management.
• Managing data is important for data integrity in organizations.
• Organizations maintain security in databases.
• Databases may be electronic and manual.
• Examples of manual databases include a library card catalog.
• Electronic databases have advanced accessibility.
• There are multiple software programs:
• MySQL
• MongoDB
• PostgreSQL
• DBMSs are extremely useful because access is improved.
• Tables have advanced security factors.
• Database models are helpful in ensuring user security.
• Models include hierarchical and network patterns.
• Comparing these databases shows increased user complexity.
• A relational model is an approach in database design.
• Object relational are improved security models.
• Describing schemas includes advanced organizational methods.
• Fields represent a single piece of data.
• Organizing fields has various tables.
• It's an advanced step that is included in modern designs.
• Databases also use security tools.
• Steps involved in creating an analysis is data mining.
• MS Access tabs are a large part of modern software.
• The process of creating an account is modern in database design.
• Primary keys are an example of data architecture.