Digital Equipment DECconcentrator 500, Installation Manual, Page: 21 / 98

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Introducing the DECconcentrator 500
This chapter provides an overview and physical description of the DECconcentrator
500.
1.1 Product Overview
The DECconcentrator 500 is an American National Standards Institute (ANSI)
X3T9-compliant physical layer device for use in a Fiber Distributed Data Interface
(FDDI) network. The concentrator provides flexible application of FDDI to accom-
modate the diverse building wiring schemes at customer sites. The concentrator is
the key component in the Digital dual ring of trees topology. It supports
building and campus wiring topologies through the creation of hierarchical trees.
The concentrator is an active device and, in its simplest form, is a multiport physical
layer repeater. It decodes, retimes, and, if necessary, modifies the repeated data
stream.
1.1.1 Out-of-Band Management
The DECconcentrator 500 has a 25-pin D-subminiature connector on the input/out-
put (I/O) panel. You can connect a terminal directly to the 25-pin D-subminiature
connector. You can also connect to a terminal through a Scholar modem (or equiva-
lent).
Out-of-band management (OBM) allows you to manage the concentrator with or
without a Network Management Card. OBM does not require any special manage-
ment station or software other than a terminal.