perfSONAR project partners
perfSONAR logo

CNM

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 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 JRA1/perfSONAR tools.

Geant access network displayed via the CNM
Achievements

The tool shows the network topology using a set of hierarchical topology maps. The maps contain network nodes (routers or switches) and links including status information and metrics. In the prototypical version the link utilization is the first metric which is displayed since this metric has also been available in many networks and is retrievabel by perfSONAR Round Robin Database MAs. 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 enabled 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, or monthly 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 mechanisms supports storing user preferences (e.g. preferred maps, preferred metrics).

Currently, the tool show topological and utilisation information for Geant, SWITCH, ESnet, UNINETT, SURFnet, and CARNET.

SWITCH network topology


User guide

The application start of the CNM demands a user authentication (login/password); this allows a customisation of views based on user needs and the protection of data that should only be accessible to authorised users. The customisation is not used in the prototypical 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 prototypical 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 colours). 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 utilisation colours.

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 utilisation 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.

Example statistic for a month

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 utilisation data and other link metrics. For the links, the figure shows a graphical visualisation of the utilisation (green = low usage/lower than 15%, yellow = middle usage/between 15% and 30%, red = high usage/higher than 30%). Other metrics, which will become a vailable in the GÉANT2 environment, include delay, jitter, packet loss, and available bandwidth. 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, and monthly statistics. The next figure shows an example how a history of a link utilisation looks. The tools database stores the history of all elements for several months.

CNM architecture


Tool Architecture

The figure below 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. While the topology data has been extracted from static configuration files thus far until Topology Services (ToS) JRA1 (which will be commonly developed for use by JRA1, JRA3, JRA4 and SA3) become available, Perl scripts are used to retrieve measurement data. In perfSONAR, MAs were implemented to provide utilisation data contained in RRDs. These are accessed via SOAP/HTTP. Other types of MAs are currently under development.

Next steps

Besides the integration of additional network topologies and metrics (in particular delay, jitter, loss measurements), the tool development aims at the development of special overview capabilities for network management. This dashboard will show a set of aggregated metric values. For example, the network manager might want to know the current overall availability of the network, and how this metric has evolved over a past time period. Another interesting question is whether there are problems with the network delay in general. Therefore, it is desirable to calculate on overall delay value from the single delay values.

References

Tool download: http://sonar1.munich.cnm.dfn.de/cnm-app/def/jnlp/topoapplet.jnlp (please note that this is restricted to project partners).

Tool homepage: http://www.cnm.dfn.de/

Contact

  • Andreas Hanemann, DFN/LRZ, phone: +49 89 35831 8712, e-mail: hanemann_AT_dfn.de
  • David Schmitz, DFN/LRZ, phone: +49 89 35831 8765, e-mail: david.schmitz_AT_lrz.de