Cabletron Systems Cabletron BRIM-F6, Networking Manual

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PIMs and BRIMs
4-2 Port Interface Modules
The PIMs can be added at any time, allowing a Network Manager to add
capabilities for special links at any time. Originally developed for use in the
Cabletron Systems Media Interface Module (MIM) line for the MMAC-FNB
modular chassis, the PIMs allow a device to support an additional type of cabling
in addition to its primary cabling type. A device which was built to provide 24
RJ45 ports for connections to UTP cabling can also support a single multimode
fiber optic connection with the addition of a PIM that supports multimode fiber
optics.
In essence, the PIMs act as internal transceivers. The internalization of the PIMs
provides specific benefits over external transceivers. The internalized PIM does
not need a metal or plastic case, requires no dedicated power supply, does not
require jumper cabling, and, most important from a design point of view, only
counts as one transceiver in a network link.
Types of PIMs
To provide connectivity options for the widest variety of networking needs, and
to increase the flexibility of Cabletron Systems networking devices, there are
several types of PIMs available. These different PIMs are designated by a prefix
and a suffix. A table detailing all the currently released PIMs and the special
characteristics of them may be found at the end of this section.
Figure 4-2. PIM Decoding
The prefix of the PIM’s name (in this case “E”) identifies what networking
technology the PIM is designed for use with. Most often this prefix is the first
letter of that technology’s name (E for Ethernet, T for Token Ring, etc.). PIMs may
only be used in devices of the correct networking technology. You may not, for
example, place an Ethernet PIM in a Token Ring device. The PIM will not operate,
and may, in fact, disrupt the operation of the Token Ring network.
NOTE
As a reminder: an Ethernet network may not contain any path
where a signal passes through more than three transceivers
before reaching its destination or passing through a bridge,
switch, or repeater.
EPIM-F2
(E)thernet (F)iber Optics
Type 2
(ST Connectors)
2094n05