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The Golden Rules

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DQI Bureau
New Update

Following standards pays in terms of the life of the cabling, durability and

return on investment as one cannot possibly lay and remove cables as it were a

LAN Switch. As this forms the backbone of any company's operations, the

standards need to be respected and followed as per TIA/ EIA listed standards.

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Standards for True RoI



Abiding and following standard guidelines is more to do with

getting the right throughput and extending the life of the product. Most cabling

agencies (small operations) are not aware of the standards completely. This is

an important aspect why structured cabling solutions may not give the right

performance. However, certification concepts followed by almost all major OEMs

help the industry in this aspect. Networks should be designed for easy

installation and access, and cabling should be provided with adequate support

and protection. Manufacturers' guidelines are designed to ensure that all

these criteria are met. They also take into account national and international

standards applying to cable pathways. The installer must ensure that the

requirements of building codes and standards are met in full.

Cost vs Performance



In India, the choice of any product would be based on the

cost as it is a known fact that major OEMs follow TIA/EIA standards. While the

cable and component manufacturers follow the TIA/EIA standards, the durability

of the system would depend on the material used in manufacturing such cables and

components. Product (standards) compliance for some is more an art form than a

science, and there are very valid reasons why one patch cord sells for lesser

while another sells for a higher price. Likewise, installation practices alone

can take a first-class product and turn it into a mediocre one in an instant.

When contractors are driven by the knowledge that price is a foremost

consideration, be assured that shortcuts will occur-only a matter of where and

how many.

However, the central challenge to an end user today is to

truly define his needs-present and future. Cabling decisions that will hold

their value throughout performance and time.

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An important question that builds the premise for all the

compliance/standard issues is what should be the performance of a structured

cabling system?

The Performance Issue



Some prioritize link performance, others prefer channel

performance. How do you distinguish between what you understand and what

performance you are really buying-and be sure of what you get?

The channel is the entire cabling system comprising all the

cables, connecting hardware such as outlets and patch panels and all the cords

between (but not including) the mated plug/socket in the network interface card

(NIC) used in your PC at one end and the communications room equipment,

typically a switch, at the other. The performance requirement of the channel is

actually handed down to the cabling industry by the groups who define 'applications'

such as Ethernet, ATM, SDH and the like. These specifications basically say

"If the dc resistance is better than A Ohms, the insertion loss is better

than B dB, the signal to noise ratio is better than C dB, crosstalk is better

than D dB, the return loss is better than E dB, etc, then the application will

work over the channel". These groups that define the applications are only

interested that an RJ45 plug is at each end of the channel to fit into the RJ45

sockets provided. They are not very rigorous about the processors.

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Standards Galore



Even the different structured cabling standard bodies use

different definitions! In ISO/IEC11801:2002 and EN 50173-1:2002, a compliant

channel can be any collection of cables, connectors and cords that, as a cabling

system, meet the channel performance requirements. Whereas under the American

standard, TIA/EIA-568-B, a channel must be constructed of individually compliant

cabling components. And, of course, if the individual components are not Cat5e

or Cat6 compliant, then there is very little chance of the channel continuing to

meet its specified performance requirement should a different manufacturer's

patch cord, outlet jack or patch panel be introduced later on-leading to

network performance problems and reduced throughput.

Structured

Cabling Standards' Specification

Ethernet Bit

Rate
Central

Transmission
Pairs Carrier Min

Category of
Rated

Frequency
Encoding/ 
Standard   Frequency used   Cabling

required
of

Cable
Technology

used
100

Base T4
100

Mbps
33.33

MHz
4 Copper Category

5E
100

MHz
Ternary

8B6T
100

Base TX
100

Mbps
100

MHz
2 Copper Category

5
100

MHz
MLT-3
1000

Base T
1

Gbps
62.5

MHz
4 Copper Category

5E
100

MHz
PAM5
1000

Base TX
1

Gbps
125

MHz
2 Copper Category

6
250

MHz
4B/5B
10G

Base T
10

Gbps
500

Mhz*
4 Copper Augmented

Category 6
Min

500 MHz
PAM12
1000

Base LX
1

Gbps
NA NA Fiber Single

Mode
- 8b/10b
1000

Base SX
1

Gbps
NA NA Fiber Multi

Mode (OM1, 2, 3)
- 8b/10b
10G

Base FX
10

Gbps
NA NA Fiber Multi

Mode (OM3)
- -

A permanent link, as defined in ISO/IEC and EN, includes the

horizontal cabling from the horizontal patch panel jack in the communications

room through to the telecommunications outlet jack at the workplace-including

the mated connectors at each end. The permanent link is defined because, in most

cases, when a cabling system is being installed, the channel (which also

includes all the additional cords and connections) simply doesn't exist.

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The whole point of cabling standards is to be able to plug

together cabling components from different manufacturers and still meet the

overall channel requirement. You don't want a situation where an end user is

mixing compliant and non-compliant products. So, to ensure that cabling

components from different manufacturers will interoperate, we have Cat5e and

Cat6 component requirements. It's possible for poor terminations and wire map

errors to occur or for jacks and plugs to become damaged. And cables are all too

easily crushed, kinked or damaged on site during installation. So, cabling

components can cease to be component compliant with the result that channel

performance is hindered. In reality, it is imperative to test on site after

installation.

Although the standards allow for a great diversity of

proprietary solutions, 100% customers want to buy a system that is true Cat5e or

Cat6, ie, it's the fully interoperable, fully component compliant option. And

they can only achieve this by specifying that all of the cabling components in

the solution are fully component-compliant to the standards.

There is a defining way to measure product capability and

creating a level playing field. Ensure that all of the cabling components in the

system offered comply with Cat5e (or Cat6) according to ISO/IEC 11801:2002, EN

50173-1:2002 or TIA/EIA-568-B. Users should decide for themselves whether they

value the comfort of a safety margin or headroom and should totally discount

irrelevant claims about additional bandwidth and channel performance.

Minu Sirsalewala

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