Lecture 2

Network Management Basics

Instructor: Dr. Jie Gao
Course: NET3006A Network Management and Machine Learning
Academic Term: Winter 2026
Usage Restriction: For registered students in NET3006A only.

Overview

• Key Topics Covered:

  • Network Performance

  • The Need for Network Management

  • Definition of Network Management

  • Network Management Technologies

  • Network Management Components

Network Performance

• Metrics of Network Performance:

  • Delay: Time taken for a packet to travel from source to destination.

  • Packet Loss: Instances where packets being sent across the network are not successfully received.

  • Network Throughput: Rate of successful data transfer over a link or path.

• Reference Text: Computer Networking: A Top Down Approach, by James Kurose and Keith Ross (Sections 1.4).

Packet Delay

• General Concept:

  • A packet travels from source to destination via multiple intermediate nodes.

  • During transit, a packet experiences various types of delays.

• Types of Delays:

  • Processing Delay: The time taken by routers to process packet headers, forward packets, and check for errors.

  • Analogy: Like checking a passport and booking info at an airport.

  • Typical Duration: Microsecond scale (10⁻⁶ s).

  • Queueing Delay: The wait time before packets are transmitted onto an outbound link.

  • Analogy: Waiting in a line for check-in or boarding at an airport.

  • Factors Influencing Delay:

    • Other packets may already be at the same node.

    • Outbound links might be busy.

    • Queueing delay can range from microseconds (10⁻⁶ s) to milliseconds (10⁻³ s).

  • Transmission Delay: The time to push all bits of a packet onto the link.

  • Formula: $ext{Transmission Delay} = rac{ ext{Packet Length (bits)}}{ ext{Transmission Rate (bits/sec)}}$

  • Analogy: From the moment the first group member steps into the elevator until the last member does.

  • Typical Duration: Microsecond to millisecond scale.

  • Propagation Delay: The time required for each bit of the packet to propagate to the next node.

  • Formula: $ext{Propagation Delay} = rac{ ext{Distance}}{ ext{Propagation Speed}}$

  • Propagation Speeds:

    • Wireless: approximately $3 imes 10^{8}$ meters/sec

    • Wired: approximately $2 imes 10^{8}$ to $3 imes 10^{8}$ meters/sec.

Delay Requirements by Applications

• Application Delay Requirements:

  • Virtual reality (VR): Less than 20 milliseconds to prevent dizziness.

  • Industrial process automation: 1 to 10 milliseconds depending on the application.

  • Vehicle-to-vehicle communication: 10 to 100 milliseconds for safety applications.

  • Discussion Question: Which types of delays are more likely to be directly addressed by hardware?

Packet Loss

• Background:

  • When queue capacity is reached in a router, newly arriving packets are dropped.

  • Example: During heavy traffic where more packets arrive than can be processed.

• Repercussions:

  • A packet may be lost if the buffer is full, leading to potential retransmission protocols for lost packets.

Throughput

• Definition:

  • The rate of successful data transmission over a link or path, excluding lost packets.

  • Units: bits/s, packets/s, or unitless.

• Types of Throughput:

  • Instantaneous Throughput: Rate at a given moment.

  • Average Throughput: Rate over a longer duration.

• Analogy: Consider throughput as a pipe size transmitting fluid; relates to end-to-end data transmission rates.

• Characteristics:

  • Link Capacity: Maximum supported data rate.

  • Bottleneck Link: The link that limits overall end-to-end throughput.

Throughput vs Delay

• Analysis:

  • The packet size affects throughput and delay.

  • Connection between throughput and delay (high throughput doesn’t always equate to low delay).

• Examples of Relationships:

  • High throughput may lead to high propagation delays if not managed properly.

  • Low throughput often correlates with low propagation delay due to high end-end efficiency of the network.

The Need for Network Management

• Purpose: Managing complex networks that consist of various equipment, managing status variations, and handling large amounts of data.

• Analogies:

  • Transportation System:

  • Monitored traffic management center for highway networks.

  • Planning and Upgrades:

  • Need for long-term infrastructure planning, like rail extensions.

  • Security Monitoring:

  • Ensuring passenger safety checks at airports.

  • Regular Maintenance:

  • Highways need maintenance in response to accidents.

  • Technological Upgrades:

  • Shifting from manual to electronic toll collection systems.

Why Network Management?

• Complexity:

  • Networks consist of diverse equipment with varying statuses over time, leading to management challenges.

• Network Examples:

  • 5G network functional architecture is highly complex, requiring comprehensive network management.

• Information Requirements:

  • Different entities require insights, e.g., ISPs need to evaluate service levels, administrators need to identify vulnerabilities, and end-users need data consumption information for billing.

• Potential Issues:

  • Various problems can occur, e.g., cable cuts, server downtime, software failures, and equipment malfunctions.

• Maintenance/Upgrades:

  • Necessary for the continued operational effectiveness of network resources, including firmware updates, hardware upgrades, and network performance optimizations.

What is Network Management?

• Definition:

  • Network Management encompasses Operations, Administration, Maintenance, and Provisioning (OAMP) of networks and services.

• Components of Network Management:

  • Involves a variety of activities, methods, procedures, and tools.

• Examples:

  • Activities include monitoring and configuration, methods include proactive/reactive maintenance, and tools might include various software applications.

OAMP – Operations

• Operational Activities:

  • Daily tasks to ensure network and service functionality.

  • Activities include Network monitoring, incident management, performance reporting, and security tool oversight.

• Comparison to Transportation Analogy:

  • Similar to maintaining smooth operations in a traffic network.

OAMP – Administration

• Administrative Functions:

  • Resource tracking and network management policy implementation.

• Examples:

  • Upgrading planning, performance evaluations, inventory tracking, address assignment, and accounting billing.

OAMP – Maintenance

• Maintenance Tasks:

  • Activities focused on the hardware and software to maintain operational integrity.

• Functions Include:

  • Software upgrades, equipment repairs, troubleshooting, and routine network diagnostics.

OAMP – Provisioning

• Provisioning Functions:

  • Designing and configuring networks to support service demands.

• Key Aspects:

  • Network design, technological tracking, equipment provisioning, and ensuring proper configuration for end-to-end service delivery.

Network Management – Aspects

• International Standards Organization (ISO) Defines Five Aspects:

  • Fault Management

  • Configuration Management

  • Performance Management

  • Security Management

  • Accounting Management

• Overlap with OAMP: Each aspect aligns with the respective OAMP component (Operations, Administration, Maintenance, and Provisioning).

Fault Management

• Purpose:

  • Engagement with concerns regarding equipment, software, or service failures.

  • Aim to restore service or equipment swiftly.

• Functionality Includes:

  • Network monitoring for fault detection, alarm generation and logging, fault diagnosis, automatic restoration, and proactive fault management.

Configuration Management

• Purpose:

  • Refers to configuring and modifying network device settings.

• Functionality Includes:

  • Configuration of managed resources, planning for modifications, auditing, synchronizing configurations, and data backup/restore.

Performance Management

• Objective:

  • Collect network statistics and tune network performance for optimization.

• Functionality Includes:

  • Performance data collection, monitoring performance metrics, recognizing patterns, optimizing configurations, and observing trends for upgrades.

Security Management

• Focus:

  • Ensuring network security against threats such as hacking attempts and viruses.

• Functionalities Include:

  • Security policy creation, user access restriction, vulnerability monitoring, traffic inspection, and port blacklisting.

Accounting Management

• Objective:

  • Tracking services offered/used and managing revenue collection.

• Functionalities Include:

  • Billing rules establishment, consumption measurement/recording, usage control, data processing, and billing generation.

Technologies in Network Management

• Technical Aspects:

  • Network management draws upon a collection of technologies including:

  • Information modeling

  • Database management systems

  • Distributed systems

  • Communication protocols

  • Artificial intelligence

Information Modeling

• Importance:

  • Central to many network management applications, representing an abstraction of the real world.

• Focus Areas:

  • Structures for information relating to network devices, user connections, service dependencies, etc.

• Example of Information Model: Common Information Model (CIM).

Database

• Necessity:

  • Persistent storage for network management data.

• Stored Data:

  • Network configurations, status information related to traffic/usage, consumer information.

• Implementation:

  • Utilization of existing database management systems for information storage.

Distributed Systems

• Components:

  • Distributed applications and systems for network management that share management loads across several operational centers.

• Benefits of Distributed Network Management:

  • Enhanced scalability, reliability, and reduced latency in management tasks.

Communication Protocols

• Functions:

  • Define rules for communication between management applications and network devices.

• Considerations Include:

  • Initiation of communication, type of messaging (event-driven vs. time-driven), and the frequency of communication.

Artificial Intelligence

• Role:

  • Facilitates automation in network management operations, enhancing manager operations based on AI.

Network Management Components

• Core Components:

  • Managed Devices: Network elements that are subject to management.

  • Network Management System (NMS): An integrated set of management tools.

  • Management Network: The communication network interconnecting management entities.

  • Management Support Organization: Responsible for operating the network using management technologies.

Key Concept – Manager & Agent

• Definitions:

  • Each application within the NMS is referred to as a manager.

  • Managed devices come equipped with software components called agents that facilitate communication with managers.

• Communication Dynamics:

  • The manager initiates communication while the agent responds and supports the manager's efforts.

Component 1: Devices (and Agents)

• Managed Devices:

  • Include switches, routers, gateways, etc.

• Agents:

  • Software implementations of management interfaces, allowing for the translation of management commands and information.

• Characteristics of Agents:

  • Consists of a management interface, a Management Information Base (MIB), and core agent logic for device communication.

Management Information and MIB

• Management Information:

  • Provides abstraction for real-world aspects of devices for effective management (e.g., software version, port utilization).

• MIB (Management Information Base):

  • A structured collection of management information to facilitate operations and communication.

Differences between MIB and Database

• Characteristics of MIBs:

  • Typically lighter and hierarchical in nature, focusing on varied types of information.

• Database Characteristics:

  • Generally heavier, requiring more processing resources, with large volumes of comparatively homogeneous data.

Managed Object vs. Real Resource

• Concept of Managed Object (MO):

  • Represents a specific aspect of a real network device, such as operational state or statistical data of a port.

• Real Resource:

  • The actual physical component corresponding to the managed object.

MIB, MOs, and Real Resources

• Conceptual Structure:

  • All real resources together represent a managed device, while MOs and their relationships embody a MIB.

Component 2: Network Management System (NMS)

• Function of NMS:

  • Provides the framework for managing network operations.

  • Includes applications like network monitoring and intrusion detection systems.

Manager – Agent – MIB Relationship

• Core Interaction:

  • The manager utilizes the agent’s MIB to send and receive requests and notifications regarding the status of managed devices.

Distributed Network Management

• Definition:

  • NMS can operate across multiple hosts for efficiency and reliability.

• Benefits Include:

  • Enhanced scalability, robustness against single points of failure, and reduced management latency.

Management Proxy and Hierarchy

• Understanding Proxies:

  • Nodes may function as proxies, assuming both manager and agent roles for various devices leading to a management hierarchy.

Component 3: Management Network

• Networking Factors:

  • Critical for ensuring communication between managers/agencies and managed entities.

  • Separate management and production networks may be established or can share infrastructure.

Management Networks: In-Band vs. Out-of-Band

• In-Band Management:

  • Uses the same network infrastructure for both management and production traffic.

• Out-of-Band Management:

  • Employs dedicated ports for management traffic, ensuring separation from production.

• Pros and Cons Comparison:

  • In-band management can lead to congestion but is cost-effective, while out-of-band enhances reliability but at a higher cost.

Dedicated Management Network: Pros & Cons

• Summary of Advantages:

  • Improved reliability, better quality of service, simplified planning, and enhanced security.

• Disadvantages:

  • Greater cost.

• Consideration:

  • In critical scenarios or large infrastructures, a dedicated pathway is warranted.

Summary of Lecture 2

• Network performance metrics: Delay, packet loss, throughput.

• Reasons for network management: performance monitoring, issue detection, maintenance, and upgrades.

• Overview of network management: OAMP; fault, configuration, performance, security, accounting.

• Technologies: information modeling, databases, distributed systems, communication protocols, AI.

• Components of network management: Managed devices, NMS, management networks.

Conclusion

• Expressed appreciation for student engagement and participation in the learning process.