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University Details

  • Year: 1427 H
  • University: Princess Nourah Bint Abdulrahman University
  • College: Faculty of Computer and Information Sciences
  • Department: Information Technology Department

Course Details

  • Course Title: Principles of Information and Technology Systems - IT 201
  • Lecture Topic: Networks & Network Management

Learning Objectives

  1. Define network fundamental concepts.
  2. Recognize Networking models.
  3. Explain the network management concept.
  4. Outline network management protocols.

Part 1: Computer Networks

Definition of a Computer Network

  • Network: A set of autonomous devices (also referred to as nodes) connected by a single communication technology.
  • Link: The connection between two nodes.
  • Node: A device capable of sending and/or receiving data; can be a computer, printer, or any device (also called a host or end-device).
  • Connection Types: Wired (e.g., cables) or wireless (e.g., Wi-Fi), both of which transport signals carrying information.

Data Transmission

  • Data can be transmitted in:   - Analog Format   - Digital Format
  • Digital advantages: Superior noise immunity, accuracy, flexibility, high data rates, cost-effectiveness, and efficiency.

Network Switching Modes

Packet Switching
  • Data is divided into packets; sent along different communication paths; packets are reassembled at the destination.
  • Advantages: More efficient use of the network capacity.
  • Packets contain directions and error-checking information.
Circuit Switching
  • A connection is established before data transmission, and all packets follow the same route.
  • Released after transmission is complete.

Components Needed for Network Connection

  • NIC (Network Interface Card): Essential to connect a computer to a network.
  • Connection Medium: Telephone wire, coaxial cable, radio signal, etc.

Network Operating System (NOS)

  • Responsible for routing and managing communications and coordinating resources on the network.
  • Switches vs. Hubs:   - Hub: Simple device; broadcasts packets to all devices.   - Switch: Intelligent; filters and forwards data to specific destinations.   - Router: Routes packets between different networks.

Elements of a Simple Network Example

  • Network Infrastructure: NIC, PC, Switch, Server, Networking Components.

Network Classification

By Scale (Size)

  • Local Area Network (LAN): One room, building, or campus.
  • Personal Area Network (PAN): 1m - 10m.
  • Metropolitan Area Network (MAN): Covers a city; connects several LANs.
  • Wide Area Network (WAN): Nationwide; connects multiple MANs and LANs.
  • Internet: Global network connecting all types of networks (greater than 1m).

Network Types

  • Basic Network Types: LAN, WAN, MAN.

Network Transmission Methods

  1. Unicast: One sender to one receiver.
  2. Multicast: One sender to a set of receivers.
  3. Broadcast: One sender to all other hosts.

Network Topology

  • A topology describes the layout of the network.
  • Physical Topology: Describes how cables are run.
  • Logical Topology: Describes the message travel paths.

Physical Topologies

Bus Topology
  • Single cable connecting all workstations.
  • Minimum cabling but small coverage area.
  • Difficulty in maintenance; disruption occurs if cable breaks.
Star Topology
  • Branches each device off a central device (hub, switch, or router).
  • Easy to add workstations; failure of one does not affect others.
Ring Topology
  • Each computer connects with two others, forming a circle.
  • Messages travel in a unidirectional path; downtime occurs if one entity is removed from the ring.

Networking Models

Client/Server Model

  • Servers provide resources necessary for client tasks; clients send requests and receive responses.

Peer-to-Peer Model

  • Decentralized structure; hosts can change roles between client and server.

TCP/IP Network Architectural Model

  • Four-layer framework:   1. Link Access   2. Internet   3. Transport   4. Application
  • Combines TCP (for reliable connections) and IP (for addressing and routing).

Part 2: Network Management

Purpose of Network Management

  • Involves administering, configuring, monitoring, and maintaining a network for reliability, performance, and security.
  • Aims to provide accessible, high-quality resources and support business continuity.

Key Processes in Network Management

  1. Operations: Daily network service operations.
  2. Administration: Establish goals, policies, and network management procedures.
  3. Maintenance: Installation, repairs, and ensuring operational efficiency; involves Help Desk coordination.
  4. Provisioning: Planning and designing networks, including introducing new technologies.

Key Functions of Network Management

  • Fault Management: Detect and resolve faults.
  • Configuration Management: Manage settings and changes.
  • Accounting Management: Track usage for billing and planning.
  • Performance Management: Monitor metrics like throughput and latency.
  • Security Management: Control access and detect security breaches.

Network Operations Center (NOC)

  • Central location where network operations are monitored and maintained.
  • Responsible for generating reports and gathering statistics for management and users.

Key Components of Network Management System (NMS)

  1. Simple Network Management Protocol (SNMP)
  2. Structure of Management Information (SMI)
  3. Management Information Base (MIB)
Simple Network Management Protocol (SNMP)
  • Application-layer protocol for network management and monitoring.
  • Supports three versions: SNMPv1, SNMPv2, SNMPv3.
  • Utilizes a manager-agent model to monitor devices and collect data.
SNMP Message Types
  • Trap/Informs: Notifications regarding events; Informs are acknowledged while Traps are not.

Components of SNMP

  • SNMP: The communication protocol.
  • MIB: The structured database of device information.
  • SMI: The syntax used for defining data types and organization in MIBs.
SNMP Flow of Events
  1. Queries are sent from a manager (SSP) to Agents (Routers, Switches).
  2. MIB collects the device data.
  3. Responses are sent back to the manager for analysis.

References

  1. Data Communications and Networking, Sixth Edition, 2021 - The McGraw-Hill Companies, Inc. - Chapters 1 & 12.