Cabletron Systems MMAC-5FNB, Сетевое руководство

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Technology Basics
3-14 Token Ring
Cost : Token Ring equipment is inherently more specialized, and often more
complex, than Ethernet equipment with similar capabilities. This, in conjunction
with the relatively smaller number of Token Ring networking hardware suppliers,
tends to make the cost of implementing a Token Ring network more expensive
than the implementation of an Ethernet network with a similar number of users.
As with the complexity of configuration, the cost of Token Ring networking
devices is partially dependent upon the choice of media and the selection of active
or passive circuitry.
Segmented Token Ring
Performance : Combining the transmission speed and consistent availability of
the Token Ring technology with the segmentation and isolation afforded by
bridging creates a very capable network design. The segmentation of Token Rings
into workgroups provides for greater network availability and for the
configuration of a greater number of workstations and other nodes in the network
as a whole.
Reliability : The automatic fault detection and isolation features of the Token Ring
technology add to the reliability of the multiple bridged Token Ring network. The
incorporation of bridging adds an additional layer of complexity which may be
difficult to manage, but the operation of the bridges keeps network problems on
one Token Ring from affecting other Token Rings in the network.
Ease of Configuration : The segmented Token Ring is the most complex network
technology treated in this Networking Guide. The inherent complexity of design
and configuration of a Token Ring network is added to the requirements of
segmentation and bridging decisions. For those who fully understand the Token
Ring technology, or have some experience designing single Token Ring networks,
the move to a segmented Token Ring network is a simple one. For those with little
or no experience in Token Ring networking, the design of a segmented Token
Ring network is a somewhat intimidating, but by no means impossible, task. As
with all bridged technologies, the use of careful forethought, patience, and
planning will serve to greatly reduce the difficulty of designing a segmented
Token Ring network.
Troubleshooting : The use of multiple Token Ring networks provides for superior
streamlining of the troubleshooting process. The inherent fault isolation and
recovery capabilities of the Token Ring technology, combined with the segment
isolation provided by the use of bridging, allows for the quick and automated
location and elimination of most common error conditions, and the continued
operation of other Token Rings in the event of a fatal error condition on one ring.
Cost : Segmented Token Ring configurations require that a series of individual
Token Ring networks be set up, then connected with Token Ring bridges. These
bridges introduce the additional costs associated with the segmented Token Ring
configuration. As these bridges are reasonably complex devices, the added cost is
not insignificant. Also, whenever a new ring is created, it is necessary to supply a
Token Ring management module to support and initialize the ring.