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3 C O M
®
N J 10 0 N E T W O R K J A C K
This unmanaged
network device is
fully compliant with
BICSI TIA 568A and
TIA 569A cabling
installation
standards.
4
3Com NBX System and the
3Com Network Jack
Will the 3Com NJ100 Network Jack
forward power to a 3Com NBX
handset if the 3Com Network Jack
Multiport Power-over-Ethernet
Midspan Solution (3CNJPSE24) is
powering the system?
No. The 3Com NJ100 Network Jack
and 3Com Network Jack Multiport
Power-over-Ethernet Midspan Solution
are designed to meet the current
version of the proposed 802.3af
Power-over-Ethernet specification.
As a result, they use a resistive power
discovery scheme. Any device
plugged into it must have a resistive
signature in order to have power for-
warded to it by the 3Com NJ100
Network Jack. Currently, the 3Com
NBX handset does not have a resistive
power discovery scheme.
In addition, the 3Com NBX handset
is designed for a 24 V system. The
802.3af specification is 48 V, as is
the 3Com NJ100 Network Jack. The
only way for an NBX handset to run
through a 3Com NJ100 Network Jack
today is if the handset has its own
local power source.
Are there plans to enable the 3Com
NJ100 Network Jack to power a
3Com NBX handset in the future?
We anticipate that IEEE will ratify
the 802.3af standard. Subsequently,
other networking products will most
likely transition to supporting this
type of Power-over-Ethernet. In the
interim, we are exploring possible
power options.
Traditional Wiring and
Current Installation Practices
What are the standards that govern
cabling in buildings?
TIA 568A and TIA 569A are the basic
standards. BICSI is generally recog-
nized as the governing body for the
professional cabling industry.
Will my cabling remain TIA 568A- and
TIA 569A-compliant after installing
the 3Com NJ100 Network Jack?
Yes. The 3Com NJ100 Network Jack
is a network device that complies
with TIA 568A and TIA 569A stan-
dards. Installing the network jack
terminates the Ethernet connection
to a switch port.
How does this fit with a structured
cabling system?
Connection from a structured cabling
system (SCS) to the 3Com NJ100
Network Jack is no different than
the connection from an SCS to an
Ethernet NIC in a PC. When connect-
ing an SCS and NIC, horizontal
cabling is pulled to the user's work-
space and terminated to a female
RJ-45. The cable and connector
integrity are tested following TIA-
established methods. An approved
patch cord connects the female RJ-45
to the NIC.
In a similar way, the connection
between an SCS and the network jack
is established with a factory-tested
male-to-male cable. The network jack
presents the same interface back to
the switch as an Ethernet NIC in a PC.
The integrity of the signaling through
the network jack is tested at the fac-
tory and is also verifiable by the
installer using an optional test unit.
The procedure for doing this is estab-
lished as part of the 3Com Approved
Network Jack Installer Program.
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