Specifications

TOKEN RING OVERVIEW
2-22
TOKEN RING MANAGEMENT
According to the IEEE 802.5 standards, each ring station or Network
Interface Card (NIC) has the ability to perform the following network
management functions:
• Monitor soft and hard errors
• Maintain details of the configuration, such as the Nearest Active
Upstream Neighbor (NAUN)
• Control various parameters such as the token priority, ring
number, etc.
The above functions are the normal features installed by each
manufacturer. In each NIC there is a network management “Agent” that
communicates with the network management “product.” The “product”
has four (4) different functions:
• Supervises network operation with its Active Monitor (AM) and
Standby Monitors (SM).
• Collects error reports by way of its Ring Error Monitor (REM), from the
NICs and AM and SMs.
• Signals a particular station to remove itself from the ring, through its
Configuration Report Server (CRS), which also holds the current
network configuration, and regulates the individual NIC parameters
such as its access priority.
• At the time of insertion into the ring the “product” assigns the
operational parameters to the station via the Ring Parameter Server
(RPS).
The “agent” communicates with the product through a series of 25 AMC
frames. The MAC frame is built and transmitted to one of several
functional addresses in the product. There are four (4) functional
addresses in the product:
• The Active Monitor - C00000000001H
• Ring Parameter Server - C00000000002H
• Ring Error Monitor - C00000000008H
• Configuration Report Server - C00000000010H
Since the above entities have unique addresses, any information sent to
one of the addresses can be seized for subsequent analysis. Should there
be a fault on the network, the administrator can recapture the data at any
one of these addresses and isolate the problem with the help of analysis
tools. As mentioned previously, ring management depends on the 25
MAC frames. The following paragraphs provide a brief description of
each MAC frame.