1000BASE-T5   
 

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1000BASE-T5 Criteria

1. Broad Market Potential
Broad set of applications
Multiple vendors, multiple users
Balanced cost, LAN vs. attached stations
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Faster CPUs, graphic applications and general increases in network traffic
are forcing the development of new LANs with higher bandwidth. Most
Ethernet networks today incorporate nodes and cabling capable of 100 Mb/ s
operation. State-of-the-art network servers today can generate network
loads of more than 400 Mb/ s. A 1996 survey of 100 companies by Currid &
Company found that more than 40% of the respondents indicated that they
would need 100Mb/ s-1000Mb/ s backbone solutions by the year 2000. Many
network backbones already require bandwidth in excess of 100 Mb/ s today;
some applications do as well.

Many applications and environments will benefit from this capability:
Building-level backbone, server and gateway connectivity
Multimedia, distributed processing, imaging, medical, CAD/ CAM and
pre-press applications
Aggregation of 100 Mb/ s switches
Upgrade for large installed base of 10/ 100 Ethernet
Upgrade for large installed base of Category 5 cabling and Class D links

Market surveys indicate that Category 5 balanced copper cabling is the
predominant installed intra-building horizontal networking media today (see
# 5 below.) The market acceptance of 100BASE-TX is a clear indication that
copper cabling will continue to be the medium of choice wherever it can be
applied. 1000BASE-T is the natural extension of this evolution and can
expect broad market acceptance as the demand for network speed increases.
1000BASE-T will continue the Ethernet tradition of providing balanced cost
solutions.

Interest in 1000BASE-T has been demonstrated by the attendance of more than
fifty vendor and user representatives at technical meetings at the November
'96 Plenary, attendance at a subsequent Interim meetings, and by
participation in an email forum devoted to facilitating technical
development in this area. More than 29 vendor companies have indicated
that they plan to participate in the standardization of 1000BASE-T. This
level of commitment indicates that the standard will be supported by
multiple vendors, and that there will be a wide variety of equipment
available to support gigabit speed applications copper links.


2. Compatibility with IEEE Standard 802.3
Conformance with CSMA/ CD MAC, PLS
Conformance with 802.2
Conformance with 802 FR
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The proposed standard will conform to the CSMA/ CD MAC with currently
authorized extensions, appropriately adapted for 1000 Mb/ s use.

In a fashion similar to the 100BASE-T standard, the current physical layers
will be replaced with new Physical Layers (PHY) as appropriate for 1000
Mb/ s operation over the defined link: a link which meets the link
requirements of 4 pair Category 5 100 ohm balanced copper component
specifications as specified in ANSI/ TIA/ EIA-568-A or ISO/ IEC 11801 : 1995 and the
channel specifications of TIA/ EIA568A Annex E.
1000BASE-T offers the maximum compatibility with the current installed base
of more than 60 million CSMA/ CD nodes, most of which copper cabling systems.
Support of 802.3 Auto-Negotiation will ensure that 802.3 UTP
solutions continue to be auto-configuring.

The Management Information Base (MIB) for 1000BASE-T will maintain
consistency with the current 802.3 MIB for 10/ 100 Mb/ s operation, allowing
a consistent management model across all operating speeds.

Conformance with 802.2 is provided by the overlying 802.3z MAC sublayer.
The proposed standard will conform to the 802 Functional Requirements
Document, with the possible exception of the Hamming distance.

The 1000BASE-T PHY will conform to the Gigabit Media Independent Interface
(GMII) to be specified in 802.3z.

Two kilometer network spans, while not supported specifically by
1000BASE-T, will be supported by combination with other members of the 802.3 family of
1000 Mb/ s standards.

3. Distinct Identity
Substantially different from other 802.3 specs/ solutions
Unique solution for problem
Easy for document reader to select relevant spec
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The proposed standard is a 1000Mb/ s upgrade for 802.3 users based on the
802.3 CSMA/ CD MAC.

It will be the only balanced copper solution for 1000 Mb/ s capable of
providing service over the defined link. As such, it offers an easy upgrade
for the 1000s of users who have installed Category 5 cable plants.

It is substantially different from other 802.3 copper solutions in that itsupports 1
Gb/ s operation over the defined link.

The proposed standard will be a supplement to the existing 802.3 standard and
supplements in progress and will be formatted as a new clause, making it easy for the
reader to select the relevant specification.

4. Technical Feasibility
Demonstrated feasibility
Proven technology
Confidence in reliability
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Technical presentations given to 802 have demonstrated the feasibility of using the
digital signal processing technology in Category 5/ Class D UTP network topologies at a
rate of 1000 Mb/ s. These solutions build on current 802.3 technologies, including
100BASE-TX and 100BASE-T2, and on technologies currently in use in other data
communications areas.

In spite of the increased data rate, the signaling bandwidth required of each of the
line coding implementations currently under consideration for 1000BASE-T is no greater
than that required for 100BASE-TX. All of the line codes proposed have been simulated
in mathematical models that have been verified by actual measurements and are widely
accepted by the field as being a valid indicator of real life performance. Significant
work has been done testing line code proposals over the defined link using simulation
and actual cable links.

Experience with equipment using ADSL, HDSL and QAM based signaling techniques in the
field has demonstrated the reliability of signaling techniques such as those proposed
by 1000BASE-T. Similar modulation systems are widely used in cable modems, hard disk
drives, etc.

5. Economic Feasibility
Cost factors known, reliable data
Reasonable cost for performance expected
Total installation costs considered
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The line code solutions proposed for 1000BASE-T are all based on existing
data communications solution technologies.

Although an accurate cost model cannot be established until the line code solution has
been selected, projections indicate that the cost/ performance ratio for 1000BASE-T vis--
vis 100BASE-TX will be about the same as that offered by 100BASE-TX vis-a-vis 10BASE-T
at the time of initial introduction (1994.) The cost of proposed implementations are
expected to be 4-6X that of 100BASE-TX. Given consistent progress on the standard,
initial silicon implementations should be available in 1H98.

Customers will be able to use existing Category 5 balanced copper cabling that conforms
to the defined link. The cost model for horizontal copper cabling is well established.

A variety of surveys conducted over the past five years have demonstrated that Category
5 cabling is the dominant cabling in place today. Payne (92) found that 65% of the 117
companies surveyed had Category 5 cabling as a corporate standard and projected that
the number would grow to 83% in two years (1994.) A Sage Research survey (95) found
that 70.5 percent of surveyed companies with more than 1000 employees used Category 5
cabling for horizontal links.

For companies with installed Category 5 wiring, 1000BASE-T offers the lowest cost
Gigabit solution; all upgrade costs will reside in the silicon and magnetic components,
not the link.

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Copyright 2002 yvind Haugland
Sist endret:  13 januar 2019
 

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