Token Ring Extensions

As noted, the first version of RMON defined media-specific objects for Ethernet only. Later, media-specific objects for Token Ring were added.

Token Ring MAC-Layer Statistics This extension provides statistics, diagnostics, and event notification associated with MAC traffic on the local ring. Statistics include the number of beacons, purges, and IEEE 803.5 MAC management packets and events; MAC packets; MAC octets; and ring soft error totals.

Token Ring Promiscuous Statistics This extension collects utilization statistics of all user data traffic (non-MAC) on the local ring. Statistics include the number of data packets and octets, broadcast and multicast packets, and data frame size distribution.

Token Ring MAC-Layer History This extension offers historical views of MAC-layer statistics based on user-defined sample intervals, which can be set from 1 second to 1 hour to allow short- or long-term historical analysis.

Token Ring Promiscuous History This extension offers historical views of promiscuous (i.e., unfiltered) statistics based on user-defined sample intervals, which can be set from 1 second to 1 hour to allow short-term or long-term historical analysis.

Ring Station Control Table This extension lists status information for each ring being monitored. Statistics include ring state, active monitor, hard error beacon fault domain, and number of active stations.

Ring Station Table This extension provides diagnostics and status information for each station on the ring. The type of information collected includes station MAC address, status, and isolating and nonisolating soft error diagnostics.

Source Routing Statistics The extension for source routing statistics is used for monitoring the efficiency of source-routing processes by keeping track of the number of data packets routed into, out of, and through each ring segment. Traffic distribution by hop count provides an indication of how much bandwidth is being consumed by traffic-routing functions.

Ring Station Configuration Control The extension for station configuration control provides a description of the network’s physical configuration. Amedia fault is reported as a “fault domain,” an area that isolates the problem to two adjacent nodes and the wiring between them. The network administrator can discover the exact location of the problem—the fault domain—by referring to the network map.

Some faults result from changes to the physical ring—including each time a station inserts or removes itself from the network. This type of fault is discovered through a comparison of the start of symptoms and the timing of the physical changes. The RMON MIB not only keeps track of the status of each station but also reports the condition of each ring being monitored by a RMON agent.

On large Token Ring networks with several rings, the health of each ring segment and the number of active and inactive stations on each ring can be monitored simultaneously. Network administrators can be alerted to the location of the fault domain should any ring go into a beaconing (fault) condition. Network managers also can be alerted to any changes in backbone ring configuration that could indicate loss of connectivity to an interconnect device such as a bridge or to a shared resource such as a server.

Ring Station Configuration The ring station group collects Token Ring–specific errors. Statistics are kept on all significant MAC-level events to assist in fault isolation, including ring purges, beacons, claim tokens, and such error conditions as burst errors, lost frames, congestion errors, frame copied errors, and soft errors.

Ring Station Order Each station can be placed on the network map in a specified order relative to the other stations on the ring. This extension provides a list of stations attached to the ring in logical ring order. It lists only stations that comply with IEEE 802.5 active monitoring ring poll or IBM trace tool present advertisement conventions.