Download Key points for EIA/TIA – 570 (THE RESIDENTIAL NETWORKING

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Key points for EIA/TIA – 570 (THE RESIDENTIAL NETWORKING STANDARD)
In October 1999, the EIA/TIA approved a formal standard for residential networks. The title is ANSI/TIA/EIA-570-A
Residential Telecommunications Cabling Standard. As mentioned above, this standard is derived from the usual
EIA/TIA 568 standard for structured cabling systems.
Following are several of the EIA/TIA 570 standard's key points:
Daisy chaining of telephone circuits long the standard is out. Instead, each outlet must have its own home run. This is
called a star topography.
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The 100-meter link length is carried over from EIA/TIA 568.
Two grades of cabling, jacks and distribution devices are specified: Grades 1 and 2.
Grade 1 cabling may be Cat. 3, which will not likely be used. Grade 2 cabling must be Cat. 5, with Cat. 5e
recommended.
Grade 2 distributive devices are required to be larger than Grade 1 devices.
Grade 1 outlets terminate one 4-pair UTP cable and one 75-Ohm coax cable. Grade 2 outlets terminate two 4pair UTP cables, two 75-Ohm coax cables and provide for an optional optical fiber termination.
At least one outlet must be provided in each kitchen, bedroom, family/great room and den/study. It is
recommended that one outlet be provided for each 12 feet of unbroken wall space.
The eight-position modular jack is the only UTP jack allowed for the outlet and it shall be wired in the A
configuration. The six-position RJ-11 is not allowed. Additionally, splitting of pairs is only allowed with an
external adapter; not behind the outlet.
The standard specifies a Distribution Device (DD) for each residence. This device is a panel of sorts,
functioning as a type of service entrance panel for the telephone, cable TV and broadband services to the home.
Location, space and electrical power requirements are provided in 570: The DD must be located in a
centralized, accessible location in the tenant space, if practical. This is to minimize the length of outlet cables
and to allow for easy maintenance and configuration of the DD.
Space allocations for the DD are provided based on grade and number of outlets served. The recommendations
are provided based on the spacing between wall studs. A non-switchable 15A duplex outlet is required at the
DD for Grade 2 systems and recommended for Grade 1. The standard also makes recommendations for multitenant dwellings and backbone-cabling infrastructure.
The required testing for residential networks is not as rigorous as that for commercial networks. Commercial
systems go through a difficult testing process called certification: home cabling systems go through a less
difficult process called verification. Verification assures that the cabling system is continuous (that is, it has no
shorts or open circuits) and that the correct terminations have been made. Verification, unlike certification, does
not measure the information-carrying capacity of the link. This is considered unnecessary because residential
links are nearly always considerably shorter than commercial links and suffer much less from attenuation a
significant factor in a link's capacity. In the shorter links, near-end cross talk (NEXT) and far-end cross talk
(FEXT) are a much-reduced concern.
The primary test for residential links is the wiremap test, verifying the pin connections on both ends of the link. This is
not to say that there is anything wrong with doing a complete certification with the much more expensive Cat. 5 tester;
but it's not necessary for normal residential links.