Network Manager architecture

The Network Manager architecture can be divided into three layers: network layer, data layer, and visualization layer.

Network: The network layer interacts directly with the network. This layer contains network discovery and polling functionality. Network discovery retrieves topology data and network polling retrieves event data.
Data: The data layer stores the topology data retrieved by network discovery and the event data retrieved by network polling. Network polling also includes storage of polled SNMP and ICMP data for reporting and analysis. This layer also provides root cause analysis functionality that correlates topology and events to determine the source of network faults, and event enrichment functionality that adds topology data to events.
Visualization: The visualization layer provides the tools operators and administrators need to view topology, view events, and run network troubleshooting tools.

The following figure shows a conceptual overview of the Network Manager functional layers. Note the following points when consulting the figure:

It is possible to configure the Network Manager to include failover. This is not shown in the figure.
Network Manager is designed to be installed with Tivoli Netcool/OMNIbus to enhance fault management, including root cause analysis, and correlation of alerts with the network topology.

This figure depicts a standard Network Manager installation, and shows Tivoli Netcool/OMNIbus handling the storage and management of network events and the Tivoli Netcool/OMNIbus Web GUI handling visualization of network events.

Note: Tivoli Netcool/OMNIbus is a separate product. If you do not already have OMNIbus then you must get a copy and install it. For more information, see the Network Manager installation documentation. Note also that Network Manager is a key component within that solution, where it is also tightly integrated with Netcool/Impact, and IBM Operations Analytics - Log Analysis.
The Dashboard Application Services Hub GUI framework is an application that runs GUIs from different Tivoli® products, including Network Manager. The GUIs represented in the following figure, including the topology visualization GUIs and the event visualization GUIs all run within the Dashboard Application Services Hub GUI framework.
- The topology visualization GUIs include single-widget views, such as the Hop View, Network Views, and Structure Browser. Default topology views also include multi-widget views, such as the Fault-Finding View and the Network Health View.
- The Tivoli Netcool/OMNIbus Web GUI event visualization GUIs include the Event Viewer.
- Network administrators can also build their own multi-widget views, which customize combinations of the single widget views.

Concept overview of Network Manager — Figure 1. Network Manager functional layers

Network discovery

Network discovery involves discovering your network devices, determining how they are connected (network connectivity), and determining which components each device contains (containment). The complete set of discovered devices, connectivity, and containment is known as a network topology. You build your network topology by performing a discovery and then ensuring that you always have an up-to-date network topology by means of regular rediscoveries.

Network polling

Network polling determines whether a network device is up or down, whether it has exceeded key performance parameters, or whether links between devices are faulty. If a poll fails, Network Manager generates a device alert, which operators can view in the Event Viewer.

Topology storage

Network topology data is stored in the Network Connectivity and Inventory Model (NCIM) database. The NCIM database is a relational database that consolidates topology data discovered by Network Manager.

Event enrichment

Event enrichment is the process by which Network Manager adds topology data to events, thereby enriching the event and making it easier for the network operator to analyze. Examples of topology data that can be used to enrich events include system location and contact information.

Root-cause analysis

Root cause analysis is the process of determining the root cause of one or more device alerts. Network Manager performs root cause analysis by correlating event information with topology information. The process determines cause and symptom events based on the discovered network device and topology data.

Event storage

Event data is generated by Network Manager polls and also by Tivoli Netcool/OMNIbus probes installed on network devices. A probe is a protocol or vendor specific piece of software that resides on a device, detects and acquires event data from that device, and forwards the data to the ObjectServer as alerts. Event data can also be received from other event sources.

Event data from all of these event sources is stored in the Tivoli Netcool/OMNIbus ObjectServer.

Note: Tivoli Netcool/OMNIbus is a separate product. If you do not already have OMNIbus then you must get a copy and install it. For more information, see the Network Manager installation documentation.

Polled data storage

At any time a network administrator can set up polling of specific SNMP and ICMP data on one or more network devices. This data is stored in the NCPOLLDATA historical polled data database. Operators can then use the Cognos Analytics viewer to run performance reports to interpret the data.

Topology visualization

Network operators can use several topology visualization GUIs to view the network and to examine network devices. Using these GUIs operators can switch between topology views to explore connectivity or associations, and to see alert details in context. Operators also have access to diagnostic tools such as SNMP MIB Browser, which obtains MIB data for devices.

Event visualization

Operators can view event lists and use alert severity ratings to quickly identify high-priority device alerts. Operators can switch from event lists to topology views to see which devices are affected by specific alerts. They can also identify root cause alerts and list the symptom alerts that contribute to the root cause.

Reporting

Network Manager provides a wide range of reports, including performance reports, troubleshooting reports, asset reports, and device monitoring reports. Right click tools provide immediate access to reports from topology maps.