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.
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.
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.
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 |
|||||||
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.
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.