Network Design and Management

• Today's lecture provides an overview of network design and management.
• The lecture covers design methodology and considerations.
• It also includes the rationale for network management, network management processes, and network management systems.

Introduction to Data Networks

• A Data Network consists of devices and circuits that transfer data from one computer or device to another.
• Data networks enable users at different locations to share resources, like ATMs.

Goals of Network Design

• The primary goal is to meet an organization's communication needs.
• Effective network design aims to increase productivity while staying within budget.

Network Design Considerations

• A comprehensive plan should be developed to achieve network design goals.
• Factors to consider: Suitability, reliability, scalability, and durability.

Role of Network Engineer/Administrator

• Network engineers install, maintain, troubleshoot, optimize, and expand networks.
• As networks grow, so do the potential problems.
• A key goal of network management is to help engineers handle the increasing complexity of data networks.
• Network Management principles should guide the design.

Network Management Process

• Network Management controls complex data networks to maximize efficiency and productivity.
• The ISO Framework for Network Management covers:
  • Configuration management
  • Security management
  • Performance management
  • Accounting management
  • Fault management

Configuration Management

• Configuration management includes gathering information about the current network environment.
• It also includes using gathered data to modify the configuration of network devices, and storing data to maintain an up-to-date inventory of components and produce reports.

Data Collection, Modification, and Storage

• Two methods of data collection: manual and auto-discovery/auto-mapping.
  • Manual collection is tedious and prone to error.
  • Auto-discovery uses ICMP and network management protocols.
• Configuration management information usually needs updates after being obtained.
• Network devices often contain many modifiable parameters.
• Examples of parameters; routers, routing tables, network interfaces, servers, application services, and operating systems.

Data Storage

• Unstructured storage, like ASCII files, is simple to read, access remotely, and administer.
• Unstructured storage drawbacks include inefficient storage, slow search, and inability to represent complex data relationships.
• Structured storage, like DBMS, efficiently stores data and allows relational data.
• Structured storage also uses versioning.
• Drawbacks of structured storage include the need for query language learning (e.g., SQL) and administrative overhead.

Benefits of Config Management

• Automatically gathers and updates data on network devices.
• Allows remote device configuration.
• Provides a central storage location for configuration data.
• Facilitates network inventory and report creation.

Security Management

• Security management involves protecting sensitive information on devices linked to a data network by controlling access points.
• This includes identification of information that is sensitive, pinpoint vulnerabilities, secure access points, and maintain the secure access points.

Security Management Benefits

• Increases confidence in using the network.
• A lack of security could lead to drastic measures, such as complete removal of network access of vital information, so proper security assists.

Performance Management

• It is ensuring networks remain accessible and free from congestion.
• This involves monitoring network devices and links to determine utilization and error rates.
• Ensuring the network provides consistent Quality of Service (QoS) by maintaining device and link capacity to avoid impacting performance.
  • Context-specific.

Performance Management Steps

• Collecting data on network device and link utilization.
• Analyzing data through statistical methods and workload modeling.
• Setting utilization thresholds.
• Using simulation to change or enhance network performance.

Performance Terms

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

Performance Management Benefits

• Reduces the chance of network congestion and inaccessibility, offering reliable service to users.
• Scheduling large data transfers for non-peak hours is an example of this.
• Helps examine network trends
• Assists content creators, content-hosting companies, network operators, and networking researchers

Accounting Management

• It is gathering network statistics that will then advise the network engineer on allocation of network resources.
• It involves gathering data, establishing metrics (RFC 1272, "Internet Accounting Background"), setting usage quotas, and billing network users.

Accounting Management Benefits

• Enables effective measurement and reporting of accounting details.
• Improves the network engineer's insight into user utilization.
• Helps make informed resource allocation decisions and ensure network users use shared resources fairly.

Fault Management

• It is the process of locating problems or faults on the data network.
• It involves detecting symptoms, isolating their cause, and correcting the problem if possible.
• Alarms typically do not include specific fault location info.

Gathering Information for Fault Management

• Two methods: interrupt driven and polling.
• Interrupt driven relies on critical events like link failure, but may not facilitate effective fault management.
• Polling finds faults in a timely manner but uses higher bandwidth, it can be implemented by using ICMP (ping).

Fault Management Benefits

• Bolsters network reliability by offering tools for rapid fault detection, isolation, and recovery.
• Maintains the presence of a completely accessible and continuously linked system between users and the network.

Network Management Systems (NMS)

• An NMS includes an underlying architecture, or platform, and set of applications.
• The architecture gives software that contains generic functionality for managing a variety of network devices.

NMS Examples

• Commercial: HP Openview, SunConnect SunNet Manager, IBM Netview
• Freeware: Net-SNMP (formally UCD-SNMP, CMU-SNMP), OpenNMS

NMS Platform Functionality

• A user interface.
• A network map.
• A Database Management System (DBMS) / Management Information Base (MIB).
• A query language.
• A customizable menu system.
• An event log.

Network Management Architecture

• An NMS platform can use centralized, hierarchical, and distributed architectures.