Concepts of Computer Networks

Explore two types of connections: point-to-point and multipoint. Compare dedicated links with a shared bus topology, and examine how traffic loads differ on each.

Explore mesh topology, where every node has dedicated links to every other node, enabling minimal traffic contention and fault tolerance, while highlighting the high hardware and cabling costs.

Demonstrates star topology, where all devices connect to a central hub, reducing cabling and routing data through the hub, but hub failure can halt the entire network.

Examine bus topology, a multipoint network with a single main cable and taps, highlighting minimal cabling and drawbacks such as signal degradation and difficult isolation.

Concepts of computer networks explain ring topology, where devices form a loop and data travels in one direction, circulating until delivery. Repeaters regenerate weak signals at each node.

Explore how networks are classified by size and distance, from local area networks to wide area networks and metropolitan area networks, with data rates and device roles.

Explore the OSI seven-layer network model with a focus on the physical layer, detailing bit encoding, data rate, bit synchronization, topology, and transmission model.

Explore the datalink layer, built on the physical layer, which adds framing, MAC addressing (48-bit physical address), and header-trailer encapsulation for error detection, flow control, and access management.

Explore the network layer's role in IP addresses, logical addressing, and routing for cross-network delivery beyond local area networks. Learn how data link uses MAC addresses for local communication.

Explore how the transport layer delivers data process-to-process within a computer using port addresses, segmentation, and flow control, supporting both connection oriented and connectionless delivery.

Study the session layer as a dialogue controller that synchronizes communication, the presentation layer's translation, compression, and encryption, and how the application layer provides access to network resources.

Explore the five-layer TCP/IP model—physical, data link, network, transport, application—and how data flows from the application layer to the destination via segmentation, addressing, and framing.

Explore line coding in the physical layer, converting data elements (bits) into signal elements and the ratio of one data element per signal element.

Explore line coding techniques in computer networks, including unipolar NRZ and polar and bipolar schemes, return-to-zero, AMI, Manchester, and differential Manchester, with encoding rules and bandwidth implications.

Explore how parity detects single-bit errors and distinguishes odd and even parity, and illustrates burst errors, while explaining error detection versus error correction in data links.

Explore how LRC, VRC, and CRC compute error-detecting codes for data blocks, using parity bits, checksums, and binary division to detect and correct transmission errors in networks.

Explore switching networks and switching techniques, including circuit switching, packet switching, and virtual circuit networks, and how switches connect end systems across networks.

Understand circuit-switched networks, where two stations use a dedicated, connection-oriented link with reserved resources for uninterrupted data delivery, guided by a circuit-switching table and a single, non-packet message.

Explore packet switching networks where messages are divided into packets and delivered on a connectionless, on-demand basis. See how switches use dynamic routing tables to forward datagrams toward destination addresses.

Explore virtual circuit networks, a combination of circuit-switching and packet-switching that uses connection-oriented setup, dynamic virtual circuit identifiers, and per-switch routing tables to deliver data via frames.

Learn how stop-and-wait flow control works with data frames, acknowledgment, and a retransmission timer to handle frame or acknowledgment loss in noisy channels.

Explore sliding window protocols, including go-back-n ARQ and selective repeat ARQ, showing how sending multiple frames per window and selective retransmission optimize data flow.

Examine intranetworking devices from passive hubs to gateways, detailing how passive hubs operate below the physical layer, connect wires in star topologies, and bridge datalink and network layers.

Understand how repeaters regenerate weak signals to maintain data integrity at the physical layer, and how active hubs enable multi-part repeaters to connect LAN segments without amplification or filtering.

bridges operate at the data link layer to switch frames by MAC addresses, using a bridge table to forward frames to ports, while acting as repeaters at the physical layer.

Explain transparent bridges where stations remain unaware while the bridge forwards frames using destination MAC addresses and port numbers. Learning is dynamic and automatic, avoiding manual configuration and preventing loops.

Routers connect different LANs and networks, forwarding packets via routing tables and protocols. Gateways operate on the application layer, usually as software on computers, directing messages to and from network.

Explore the differences between bridges and routers: bridges use MAC addresses and forwarding tables learned automatically at the data link layer, while routers use IP addresses and routing protocols.

Explore frequency division multiplexing (FDM), dividing bandwidth into multiple channels with guard bands to transmit multiple signals on a single link, via analog modulation and demodulation.

Explains wavelength division multiplexing using multiple light sources combined into one optical signal, transmitted through a fiber, and later split back into individual wavelengths using a prism or dispersion techniques.

Explore time division multiplexing, including synchronous and statistical tdm, round-robin slot allocation, and remedies for nonuniform data rates such as multi-level multiplexing and ballot stuffing.

Explain IPv4 addresses, detailing a 32-bit structure, the dotted decimal notation, and eight-bit octets (0–255), while contrasting with IPv6 and the expansive address space.

Analyze classful addressing in IPv4 by tracing class ranges, subnet masks, and subnetting to determine network ID and manage host addresses, address depletion, and wastage.

Explore the IPv4 header format, MTU concepts, and fragmentation. Identify fields like version, header length, total length, identification, flags, fragment offset, and protocol; and learn how fragmentation enables reassembly.