The FDDI Ring Manager for the HP Network Advisor protocol analyzer

Hewlett-Packard Journal, Oct, 1994 by Sunil Bhat, Robert H. Kroboth, Anne L. Driesbach

FDDI Ring Manager View. The FDDI Ring Manager view controls the display of three types of data in the top-level FDDI Ring Manager window (see Fig. 1). This view contains three subviews--one for each section, or tile, of the top window. As the view receives data, it checks its type and routes the data to the appropriate subview. When a subview receives the data object, it is responsible for processing the data and displaying it in its tile.

The top and bottom subviews in the FDDI Ring Manager view process ring status and analysis and real-time status messages and display the data in these messages in their tiles. These tiles are read-only and require a simple translation from analysis and real-time data to ASCII data before the data is displayed. The subview that controls the middle tile, the topology subview, is discussed below.

Ring Topology Subview. The ring topology subview is responsible for the mapping of the ring topology data objects (representing MACs on the network) in the middle tile of the FDDI Ring Manager window. This subview also provides generic topology display functionality that is subclassed and used by the M-port connections topology subviews (see Fig. 5) and the removed MACs topology subview (see Fig. 4). Each topology subview must work closely with its corresponding display module in the analysis and real-time environment to provide user interface navigation and "drill-down" capability for the user (see below).

Topology Mapping. When a data ADU is sent to the topology subview, it contains the information for each MAC that must be displayed in the tile. For each MAC, the subview must determine which icon needs to be displayed based on the type of network device the MAC represents (Fig. 3 shows all of the icons used by the FDDI Ring Manager). This is done by first looking up the MAC in the node list using the MAC's address (found in the ADU). If there is a match, the node list type is used. If there is no match, the generic type (concentrator or station) found in the data ADU for the MAC is used. A lookup is then done in the FDDI Ring Manager's icon dictionary to retrieve the appropriate icon for display based on the MAC's type.

The graphical icons used in the display are prebuilt and are accessed through an FDDI Ring Manager icon dictionary. The icon dictionary contains associations of the form (type, icon) where type is the key and icon is the value. The icon dictionary is stored on disk and loaded when the FDDI Ring Manager measurement is instantiated.

Once the icon is obtained, the connecting lines are drawn to the icon based on connection information included in the ADU. If a MAC has an error or warning status, or if the MAC is rooted (on the dual ring), the icon is masked with the appropriate color (red, yellow, dark blue). After all MACs have been processed, they are painted to the screen.

User Interface Navigation. A topology subview controls a tile that displays icons for up to 25 MACs at any one time. If the ring has over 25 MACs (an FDDI ring can have up to 500 nodes), a different set of MACs can be displayed. This minimizes the amount of data that needs to pass through the IEPC for a topology update. The scroll bar or cursor control keys can be used to display different sections of the ring.