Termination Facilities
The development of termination facility standards for communications cabling has been
largely defined by the telephone company's years of standardized procedures and practices.
The split-tab terminal block is well established, but new requirements for higher speeds,
with attendant control of noise and signal loss will require replacement of this block by
a new wire termination element. As defined elsewhere in this document, termination of
workstation wiring will migrate to the 110-style pin/post connector as will intra-building
sub-terminal twisted pair wiring. Inter-building telephone pair wiring will continue to
use the 66-type terminal block in both twenty-five (25) through one hundred (100) pair
configurations.
The campus Construction Standard for Communications requires protected terminals in all
new and renovated main building terminals. Communications Services continues to use the
66-block integrated with the protector modules for a primary hand-off. However the related
building punch-down for internal telephone line distribution has migrated to the 110-style
pin/post connector as implemented on the Krone eight and ten-pair modules.
The variety, capacity and implementation of the terminal wire blocks may continue to
undergo modification and adaptation to meet manufacturer's unique equipment configuration.
As the campus moved towards standardizing data cabling in the late 60's, it experimented
with patch panels that terminated work station cables on 15-pin (Ethernet) and 25 pin
(RS-232C) connectors mounted in rows and columns in large (12"x 16") metal
plates. The terminations were direct and access to the cabling was through the specific
connector. This reflected the nature of the terminal as opposed to local area network
configurations of equipment.
Category 1 - POTS (plain old telephone service) and Low-Speed Data (up to
9600 bits per second)
UCSB has a large amount of Category 1 wiring within its buildings. This is also the case
for many large organizations with thirty year-plus operating histories maintaining an
established wiring base on a single site. The telephone wiring for single and multi-line
telephone systems placed by GTE California, and in more recent years, Communications
Services, comprises a large installed base of cable, much of which has been used for both
voice and low-speed (9600 bits per second) data. The wiring is entirely acceptable for its
present uses with IBM display terminals, telephone company-provided 3002-type data
circuits, Net/One ASCII attachments, AppleTalk, and similar low-speed networks.
This installed base of telephone wiring is also surprisingly workable for a variety of
departmental local area networks, including the AppleTalk networks mentioned above and the
four-megabits per second Token-Ring Networks.
Category 2 - ISDN Data Integrated Services Digital Network (ISDN) Data (up to 4 megabits per second)
Since the early 1970's, Communications Services and a number of the larger departments,
such as Physics and Engineering, routinely installed twisted pair cables specifically for
attachment of data terminals. These cables were usually three or six pair, shielded or
unshielded. The characteristics of this cable will allow, with proper care of the
terminations, support of data speeds from 56 kilobits per second to four megabits per
second depending upon distance, shielding, and routing, with respect to electrical
interference.
Category 3 - Data Grade Media for Local Area Networks (up to 16 megabits per second)
Since 1989, a number of campus groups have installed a newer design of unshielded
twisted-pair cables suitable for services requiring the 10BaseT ten megabits per second
standard for Ethernet over unshielded twisted pair (UTP) as defined in EIA/TIA-568. With the development of super-thin plastic-coating for copper wire, it has
been possible to use a larger gauge (24) wire and maintain, and even decrease, the size of
a multiple pair cable.
Since the fall of 1985, Communications Services has standardized its workstation wiring
for new and re-modeled buildings with IBM Type-2 cable which employs both shielded and
unshielded pairs in a single sheath. Both shielded and unshielded pairs meet and exceed
the performance characteristics of the recent 10BaseT standard and will transmit and
receive at least twenty megabits per second data.
Termination Facilities
During the 1989-90 academic year at UCSB, the RJ modular plug, in four-pin and eight-pin
configurations, emerged as the standard connector for both voice and data. As a result,
modular patch panels that use the RJ-11 and RJ-45 patch panel are well established. The
wire attachment on the back of patch panels has been an Amphenol fifty (50) pin connector.
Patch panel cables in both twenty-five pair (50 pin) Amphenol cables (to the 66-block) and
the four and six-wire modular cables (to the station) are in common use. Both patch cable
types use 10BaseT compliant cable. Under the proposed standard, the 66-type terminal
blocks will be eliminated and station wire will be directly attached to modular patch
panels, intelligent hubs, or other equipment located in sub-terminals and wiring closets.
The direct attachment of workstation Category 5 cabling to the patch panel will maintain
the Category 5 performance specifications. Patch panel capacity will continue to be sized
to meet and exceed the number of workstation cables.
At the workstation end of the cable, termination is on a single, double-gang wall plate
and the cable pairs are attached to three RJ-type jacks labeled Voice, Data 1 and Data 2.
These RJ-jacks are replicated on the matching-labeled patch panels
Category 4 - High Speed Data Extended Distance Local Area Networks (up to 20 megabits per second)
As referenced above, since 1985 Communications Services has used the IBM Type-2 cabling as
the campus standard for all new installations. This cable serves two key purposes. First,
the shielded and unshielded pairs support all existing and projected data standards
simultaneously and in a common sheath. Second, it allows the consolidation of data and
voice communications in a single cable sheath.
While the Type-2 cable was originally defined by IBM to support its 16 megabits per second
Token-Ring and voice, it exceeds requirements for low-speed ASCII data attachments,
telephone company data service loops as well as the 10BaseT standard. In addition, it has
extended capacity that may meet the 100 megabits anticipated in the CDDI (FDDI over
copper) shielded pair standard. The IBM Type-2 cable is comparatively expensive on per
foot costs, including installation, particularly when compared to many of the new
plenum-rated unshielded cables now available.
It may be appropriate to evaluate the continued use of Type-2 as a campus standard for new
workstation wiring. An evaluation is prompted by three questions:
- First, will the growing dominance of 10BaseT and similar unshielded twisted pair (UTP)
based technology make shielded cable unnecessary and a poor financial investment?
- Second, as fiber production costs are reduced and fiber-based LAN equipment becomes more
common and less expensive, should the campus invest in a workstation attachment cable that
includes fiber to the desktop?
- Third, will the development of a CDDI (FDDI over copper) standard provide a
cost-effective justification for the shielded twisted pairs (STP) contained in the Type-2
or will the CDDI standard define a cost-effective alternative using unshielded twisted
pair (UTP)? EIA/TIA Technical Systems Bulletin addresses
specifications for higher speeds on (enhanced) UTP cables.
An initial response to these questions is contained in the proposed wiring standard in
Section 5 of this document.
Category 5 - Data Grade Media (up to 100 megabits per second)
Data-grade media as defined by the industry is projected for use with standards not as yet
formally adopted (e.g., Copper Distributed Data Interface (CDDI)). This definition
presently includes shielded twisted pair.National committees have now produced standards
for Fiber Distributed Data Interface (FDDI) over unshielded pairs (copper).
Category 6 - Coaxial Cable (up to 100 megabits per second)
The campus investment in coaxial cable has been substantial since the introduction of
remote IBM terminal attachment. The use of twisted pair with balun technology is
well-established for the replacement of coaxial cable for IBM SNA attachments. The
Ethernet-over-twisted pair developments, culminating in the 10BaseT standard, will
eventually replace both the thick and thin coaxial workstation attachments. Hub-to-hub
attachments will use twisted pair, coax and fiber for some period of time.
Cable television will continue to use coaxial cable technology until multiplexed fiber
arrives at the desk top or until digital processing and distribution of video signals
become cost-effective.
Category 7 - Fiber (in excess of 100 megabits per second)
The design and construction of the first phase of the campus fiber backbone in 1989-90
established campus standards for fiber cabling. While national standards have been
established for 62.5/125 micron multimode fiber and the ST-type connector, standards for
associated hardware such as termination panels, patch panels, jumper construction, and
cable protection are only now taking final form for the campus. Fiber will become the
campus backbone for inter-building data transmission, replacing the original broadband
cable plant.
The campus fiber backbone was fully implemented as a forty-eight (48) multi-mode fiber
cable. Subsequently, the campus standard has been upgraded and implemented in new building
construction to include forty-eight (48) multi-mode and twelve (12) single-mode fibers. In
late 1999, the campus standard was revised again to include forty-eight (48) multi-mode
and forty-eight (48) single mode fibers in all new building construction and renovation.
DCC
