Information Technology Reference
In-Depth Information
The IBM cabling system provides some important advantages in a mixed appli-
cation environment that may use coax, twinax, and twisted-pair terminations. The
cable has been designed to support all these types of signals using the proper
adapters or impedance matching baluns.
However, in a LAN-only environment, such as Token-Ring, the functions may
all be satisfactorily accomplished by the TIA-568-C system at a lower cost. In fact,
most estimates place the cost of an IBM cabling system installation at two to three
times that of a standard TIA-568-C installation.
Many other vendors have developed proprietary wiring patterns for cabling of data
and voice. Most of these plans support specific features of that manufacturer's
equipment and are not general purpose at all. Others incorporate variations of the
cabling systems previously mentioned. Of these, two other systems are widely used
and deserve mention.
NORDX/CDT IBDN
Another variant of twisted-pair wiring is the Integrated Building Distribution
System originally put forth by Northern Telecom, often referred to as Nortel.
The IBDN components are now marketed by NORDX/CDT, a Nortel spinoff.
This system is quite similar to the Avaya/Lucent/AT&T PDS and primarily supports
telecommunications wiring. As we saw with PDS, data networks can be run over
such systems, but the distance limitations and other installation practices must be
observed.
IBDN uses the common system of modular connectors with cross-connects
based around the BIX block. IBDN also contains fiber components, as does the
PDS. While the IBDN system is not specifically designed to match TIA-568-C
requirements, it will allow common types of network connections if the distance
limitations for the network are not exceeded. When used in accordance with the
guidelines in the standard, an IBDN installation can be said to be TIA-568-C
compliant.
All of the modular connectors, jacks, cable, and color codes of the AT&T PDS
system are common for IBDN. The interconnection component, of course, is the
BIX block, rather than the 110 block. In general, the IBDN system is compatible
with TIA-568 Structured Wiring, and its components may be substituted where they
meet the standard's performance specifications. Please refer to the PDS section in
this chapter and the BIX block section of Chapter 7 for more information.
