Specifications

Engineering Guidelines
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• It is highly recommended not to connect PCs to the phones, and to connect these on a
separate LAN infrastructure. The second port on the IP Phones can be disabled in the
SX-200 ICP through option 131 and COS setting 280. The second port on the IP Phones
can be disabled in the 3300ICP/MiVoice Business Class of Service (COS) form, option 193,
under the heading “PC Port On IP Device – Disable”. Note that although the second port
may be disabled for access, it may still be used for monitoring.
• Telecom cable is not CAT3, but CAT 3/CAT 5 can be used as telecom cable. Make sure it
really is CAT 3 or better by consulting the manufacturer of the cable, before installing the
equipment.
• Note that cables used as telecom wiring may also have different wiring pairs in the termi-
nation jacks as well as termination resistors, e.g. if ISDN has been used. These need to
be corrected, or removed. Ensure that any bell capacitors and master/slave jacks have
been removed. The cable route should be point to point without spurs or stubs. A cable
tester that uses Time Domain Reflectometry should be used to verify the integrity of cabling
runs. Visual inspection and ohmmeter tests may be insufficient. Be careful about pair split-
ting which may not be apparent on telecom cable (this is where the two pairs result in a
Tx/Rx & Tx/Rx combination, rather than Tx+/Tx- and Rx+/Rx- pairs). Ensure that any bend
radii have not been exceeded. In effect – be suspicious of an older wiring plant – Test!
• Pay close attention to wiring practices at the distribution frame and at the desktop and
ensure that these practices comply with CAT3/EIA/TIA-568 wiring standards. These stan-
dards are much more stringent than the wiring practices used for traditional voice wiring.
For example, in traditional voice cabling when an installer punched down cabling pairs on
a termination block (BIX/Krone block) it was very common to unwrap the twisted pairs from
an individual cable for ease of installation or to use untwisted cables to implement a cross-
connect. While this practice was acceptable in a voice network it will introduce problems
in a data network.
• Typically Ethernet cables are an in-house building wiring, and normally should not leave
the building. Telecom cables have special protection applied to cables used outside the
building. It may be required that routers and special cable protection be applied at either
end of the link in order to extend Ethernet outside the building.
• The EIA/TIA-568 standard provides numerous structured wiring recommendations regard-
ing the routing of cables. The CAT 3 cabling plant should comply with these
recommendations so that the chances of encountering network impairments due to
cross-talk and electrical noise is minimized.
• It is unlikely that CAT 3 cables will carry the full complement of pairs normally found with
CAT 5. Unless a phantom power feed is provided, the end devices will require separate
power feeds to operate. This may include local power units or the inclusion of a power feed
hub in series with the cable runs. Consider which devices need UPS support in the event
of power failure. The CX hardware provides phantom power feed.
• Only the SX-200 ICP CX and 3300 ICP CXi/CXi II platforms provide ports capable of
powering IP Phones directly and having CAT 3 connections. All other platforms are intended
for connection to a separate LAN infrastructure and a CAT 5 cable is required in this case.
CAT 3 may exist elsewhere in the network.