Data Networks and Network Management

• A data network is a collection of devices and circuits that transfer data between computers or devices, such as printers.
• Data networks enable users in different locations to share resources from a computer stationed elsewhere, like an Automated Teller Machine (ATM).
• The goals of network design are to meet the organization's communication needs.
• Network design aims to increase productivity and stay within budget.
• Considerations when designing a network are suitability, reliability, scalability, and durability.
• Network engineers are responsible for installing, maintaining, troubleshooting, optimizing, and expanding the network.
• Network management helps engineers handle the complexity of data networks and design based on network management principles.
• Network Management controls complex data networks to maximize efficiency and productivity.

ISO Framework for Network Management

• Configuration management
• Security management
• Performance management
• Accounting management
• Fault Management

Configuration Management

• Involves gathering information about the current network environment.
• Utilizes the data to modify the configurations of network devices.
• Stores data while maintaining an up-to-date inventory of all network components, producing various reports.

Data Collection

• Two Methods: Manual collection and Auto-discovery/Auto-mapping
• Manual collection is tedious, error-prone, and time-consuming
• Auto-discovery/Auto-mapping uses ICMP (ping, traceroute) and Network Management Protocol

Data Modifications

• After obtaining configuration management information, it usually needs to be updated.
• Network devices have many modifiable parameters: routers (routing tables, network interfaces), servers (application services, and operating systems)

Storing Information

• Methods of Storage: Unstructured( ASCII Files) and Structured(DBMS)
• Unstructured storage is easily read, easily accessed from remote locations and easy to administer.
• Unstructured storage has inefficient storage, is slow and unable to provide complex data relationships.
• Structured is highly efficient, allows user to relate information and includes versioning.
• Structured needs to learn query language use, like SQL and has administrative overheads.

Configuration Management - Benefits

• Automated gathering and updating of data on network devices.
• Allows remote configuration of devices.
• Provides central storage for configuration data, facilitating network inventory and other reports.

Security Management

• Protecting sensitive information on devices connected to a data network.
• Security management consists of identifying sensitive information, finding vulnerabilities, securing access points, and maintaining secure access points.

Security Management - Benefits

• Increases confidence in utilizing the network.
• A lack of security may force drastic measures, such as eliminating network access of sensitive information altogether.

Performance Management

• Ensuring that networks remain accessible and free from congestion.
• Monitoring Utilization and error rates.
• Helping the network provide consistent quality of service (QoS) by ensuring that the capacity of devices and links is not over taxed to the extent of adversely impacting performance.

Performance Management - Steps

1. Collect data on network device and link utilization.
2. Analyze data using Statistical analysis and Workload modeling
3. Set utilization thresholds.
4. Use simulation to determine performance.

Performance Terms

• Availability
• Bandwidth/Throughput
• Propagation
• Congestion
• Latency
• Threshold
• Utilization

Performance Management - Benefits

• Reduces the probability of network congestion and inaccessibility for a consistent level of service.
• Assists in examining network trends for content creators/hosting companies, network operators, and networking researchers.

Accounting Management

• Gathering network statistics.
• Assists network engineers in allocating resources, involving tasks like gathering data, setting usage quotas, and billing users.
• Metrics include RFC 1272: "Internet Accounting Background", Application layer – per-transaction, network layer – number of packets.

Accounting Management - Benefits

• Allows effective measurement and reporting of accounting information
• Increases the engineer's understanding of user utilization
• Helps make informed resource allocation decisions and ensures users have a fair share of shared networks.

Fault Management

• Locating problems or faults in the data network.
• Detecting symptoms, isolating the cause (correlating symptoms with potential problems), and correcting the problem if possible.
• Alarms don't give explicit location.

Gathering Information for Fault Management

• Two Methods: poling an interrupt
• Interrupt driven are critical events, but it may not facilitate effective fault management.
• Polling finds faults in a timely manner with higher bandwidth consumption, and can be implemented with ICMP.

Fault Management - Benefits

• It enhances network reliability by providing tools to aid/facilitate rapid fault detection, isolation, and recovery.
• Maintains the illusion of complete and continuous connectivity between the users and the network.

Network Management Systems (NMS)

• Comprising an underlying architecture (platform).
• A software package provides generic/basic functionality of network management for managing a variety of network devices.
• A set of applications built on top of the platform.

Example NMSs

• Commercial implementations: HP Openview, SunConnect SunNet Manager, and IBM Netview.
• Freeware implementations: Net-SNMP and OpenNMS.

Network Management Systems - Platform Functionality

• User interface.
• Network map
• Database Management System.
• Query language.
• Customizable menu system.
• Event log.

Network Management Architecture

• An NMS platform can use three architectures, Centralized, Hierarchical, and Distributed to provide functionality.