CNM

From GEANT2-JRA1 Wiki

Geant access network displayed via the CNM

1 Objectives
2 Achievements
3 User guide
4 Tool architecture
5 References
6 Contact

Objectives

In general, the term Customer Network Management (CNM) means to provide a controlled access to a service provider's management information. This access allows customers to retrieve management information which has been preprocessed according to their needs and to change the service configuration in a predefined manner.

In 1997 DFN started the development of its CNM tool to provide universities and research institutions in Germany information about the national research backbone by showing the network topology and current performance metrics using a set of hierarchical maps. Since the start of the GN2 JRA1 project in September 2004 DFN has begun to provide and evolve the CNM for its application in perfSONAR. This means to show the topology of the partner networks and the results of the measurements which are carried out by perfSONAR tools.

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Achievements

The tool shows the network topology using a set of hierarchical topology maps. The maps contain network nodes (routers) and links including status information and metrics. In the current version the link utilization is the primary metric which is displayed since this metric is available in many networks and is retrievable by perfSONAR Round Robin Database MAs (RRD MAs). Furthermore, maps are available which show delay, jitter, and packet loss measurements carried out by HADES measurement boxes. In the tool, it is not only possible to see the current situation in the network, but also to go back to a situation in the past which is possible by a time navigation function. In addition, graphs can be opened to show the course of metrics over time using statistics on a daily, weekly, monthly, and yearly basis.

The CNM tool has the capability to customize views and to limit the access to metrics. This is done using its authentication mechanism. This functionality is useful for projects which would like to use the CNM since it can offer a view onto the network connecting the partners. In addition, this mechanism supports storing user preferences (e.g. preferred maps, preferred metrics).

Currently, the tool shows topological and utilization information for Geant2, GARR, GRNET, ISTF, PIONIER (PSNC), SEEREN, SURFnet, SWITCH, UNINETT, Internet2, and ESnet.

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User guide

The application start of the CNM demands a user authentication (login/password); this allows a customization of views based on user needs and the protection of data that should only be accessible to authorized users. The customization is not used in the current version since access policies have not been defined. In addition, the user can currently select between English and German (an extension for other languages is possible, but currently not planned, since the tool is rather self-explaining).

The following figure shows the main window of the CNM application in its current version for perfSONAR. On the left, the networks are displayed as a tree allowing the user to choose between a “complete tree” and a “problem tree.” The complete tree contains all nodes and links, while the problem tree only contains those elements with the status “warning” or “down” (indicated by colors). Currently, this information is not provided by perfSONAR MAs so the status is defined as “unknown” for all elements. In addition, the option “Current/History settings” allows the user to select an arbitrary point in time to see a past situation of a network map. In the figure below, a caption is given to explain the meaning of utilization colors.

On the right side, a graphical view of the network is given. In the example, the network topology of SWITCH is shown, while the topology of the GÉANT2 access links is displayed in the figure on top of the page (DANTE’s policy only allows us to show utilization data for these links). By selecting nodes marked with a little arrow, it is possible to open a lower level map; e.g., double-clicking on SWITCH in the GÉANT2 access links map can open the SWITCH topology map.

In the menu bar, it is possible to select a metric for the nodes and a metric for the links. For the nodes metrics like the number of forwarded packets, the number of not-forwarded packets, the percentage of forwarded packets, the number of received packets, or the CPU usage of the main router could be provided. Note: currently, there are no node metrics in GÉANT2, because the work has focused on available utilization data and other link metrics. For the links, the figure shows a graphical visualization of the utilization (green = low usage/lower than 15%, yellow = middle usage/between 15% and 30%, red = high usage/higher than 30%). The same is available for HADES-related metrics such as delay, jitter, and packet loss. In sum, the graphical view gives a current overview of the whole network concerning state and performance.

Furthermore, it is possible to select a node or a link to display the course of a related metric for this element. It can be selected between daily, weekly, monthly, and yearly statistics. The next figure shows an example how a history of a link utilization looks. The tool's database stores the history of all elements for several months.

The Dashboard is an additional functionality of the CNM which provides an analysis of the data. In the Key Performance Indicator (KPI) window metrics are displayed which characterize the situation in a whole network. For example, there might be the question where there is any critical situation related to network utilization. The indicator therefore shows the percentage of links with a utilization higher than a threshold. The second window is used for sorting the links in a network according to the highest and lowest values. For instance, the highest utilization values can be a first indicator where upgrades may be reasonable. While this example may show a quite few changes in the top ranking links, the situation is different for other metrics. The metric "highest utilization increase" shows the largest changes in the last fifteen minutes and is therefore an indicator for reroutings.

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Tool architecture

The figure on the right shows the architecture of the CNM. The client side of the CNM Application is written in Java. It uses the tool JavaWebStart, which is also a part of the Java distribution. By using JavaWebStart, the CNM Application runs in a secure sandbox mode where the application can only access local resources if access to them is explicitly granted.

CORBA is used for the communication between client and server. On the client side, the open source Java ORB “JacORB” is used, while the open source ORB “MICO” is used for the server side.

The server is written in C++ and accesses a PostgreSQL database that stores topology and measurement data. Perl scripts are used to retrieve topological and measurement data via SOAP/HTML. While topology data is requested from cNIS (common Network Information Service) or alternatively from RRD MA metadata information, measurement data is requested from RRD MAs, SQL MAs, and HADES MAs.

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References

Tool download: http://sonar1.munich.cnm.dfn.de/cnm-app/def/jnlp/topoapplet.jnlp (please note that the password in located on wiki.geant2.net which is restricted to project partners)

Tool homepage: www.cnm.dfn.de

Additional information site: http://sonar1.munich.cnm.dfn.de/publish/Perfsonar/

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