Who
sets the standards for wiring
LAN
Cable standards are set by TIA/EIA (Telecommunications Industry Association/Electronics
Industries alliance) (or EIA/TIA depends on whose web site you are
on) e.g. Category 5 (a.k.a cat5 cat5e etc.). LAN connections/pinouts
are defined by IEEE 802.3u. Telephone wiring standards are defined
by TIA/EIA (Universal Service Order Code) (e.g. RJ48) |
Who
sets the standards for LAN wiring
LAN
Cable standards are set by TIA/EIA (or EIA/TIA it depends on whose
web site you are on as to which way round these initials are written!)
e.g. Category 5 (a.k.a cat5 cat5e etc.). LAN connections/pinouts are
defined by IEEE 802.3u. |
Who
sets the RS232 standards
RS232
standards are defined by the EIA/TIA. |
What
is category 5 (or Category 5e or Category 6) cabling.
Category
5 UTP (Unshielded Twisted Pair) cable is defined by the EIA/TIA for
use with 10 and 100 MB LANs (10baseT and 100baseT) as specification
number EIA/TIA-568A. Category 5e is a slightly improved specification
published as EIA/TIA-568A-A-5 . Category 6 is defined by EIA/TAI-568-B.2-1.
|
Does
it really matter which pairs I use.
Technically
No. BUT you have non standard wiring. This might not seem important
in the rush to fix to-days's problem but in six months time when you
come to do some more work and cannot for the life of you remember
your non-standard kluge you may think differently about standards.
Standards are not a straight-jacket - they are there to give you the
freedom to forget the problem. Ignore them at your peril. |
What
is EIA/TIA 568A and 568B wiring
EIA/TIA
568A and 568B are two wiring methods used to indicate which colors
are assigned to which pin of the modular jack |
Can
I use a DB25 connector for V.35 connections
V.35
(which no longer exists as a ITU standard - replaced by V.10/V.11)
was specified to use a 37 pin connector (the chunkiest in the world).
Nowadays for high speed serial connections (that use the term V.35)
most manufacturers use a DB25 connector but may use a non-standard
pinout. Check with the manufacturer. Here is the EIA/TIA RS-530-A
standard balanced connection pinout for the DB25. |
Is
there a difference between telephone wiring and LAN wiring
Yes
there is. Primarily do do with the way pairs are allocated in the
cables (see our primer for an explanation).
|
What
is the difference between RS232 and RS232C
RS232
defines the electrical and physical standard. RS232C indicates it
is wired using a DB25 connector (pinout diagram) rather than a DB9
(TIA 574) or an RJ45 (oops.. should say 8 Position Modular Connector)
(RS232D). |
What
is RS232D
RS232D
is the name for an RS232 connection wired using a RJ45 jack |
What
is an 8 Position Modular Connector and does it differ from a RJ45
An
8 Position Modular Connector is more commonly, but erroneously, called
(certainly by we mere mortals) an RJ45. |
Can
I run a LAN and telephones on the same LAN cable.
Depends.
If you are using 100Base-T4 standards - that is you want to use cat
3, 4 or 5 cables ALL 4 PAIRS (8 wires) ARE REQUIRED. If you are using
100Base-TX (category 5 or 5e cables only) or 10Base-T the wires numbered
4 and 5 (one pair) and 7 and 8 (another pair) are not used in normal
LAN operation but should still be connected since some equipment may
use them for special purposes (we use them for power-over-ethernet
in special applications). The spare pairs can be used for telephony
- each pair will carry a single analog line so a cat 5/5e cable can
carry 1 LAN (10 or 100 MB) and two telephone lines. However you are
taking a RISK that in the future some genius may invent a fantastic
application for one or more of these pairs and you may have to re-wire.
Whether you consider this a high or low risk is a personal decision. |
Do
I have to connect all 8 wires of a LAN cable.
If
you are using 100Base-T4 standards - that is you want to use cat 3,
4 or 5 cables ALL 4 PAIRS (8 wires) ARE REQUIRED. If you are using
100Base-TX (category 5 or 5e cables only) or 10Base-T the wires numbered
4 and 5 (one pair) and 7 and 8 (another pair) are not used in normal
LAN operation but should still be connected since some equipment may
use them for special purposes (we use them for power-over-ethernet
in certain applications). They can be used for other functions e.g.
telephony see above. Beware: You are taking a RISK that in the future
some genius may invent a fantastic application for one or more of
these pairs and you may have to re-wire. Whether you consider this
a high or low risk is a personal decision. |
Whats
the difference between 100base-T4 and 100base-TX.
100base-T4
wiring uses all 4 pairs (8 wires) and allows for the use of Cat 3,
Cat 4 OR cat 5(e) cables. If you have ANY Cat 3 or Cat 4 cabling in
your network you MUST use this standard. Most telephony cables (including
25, 50 or 100 pairs) are rated Cat 3. If your LAN uses these cables
ANYWHERE you must use 100base-T4 wiring . 100base-TX wiring uses only
2 pairs (4 wires) but can only be used with Cat 5, Cat 5e or higher
cables. |
Why
use a rack for small installations?
Even
a simple wall mount rack provides a location to mount your active
hardware (hubs, switches, modems, routers, etc.), as well as the patch
panel and cable management. This keeps all the cabling and equipment
neat, protected, and easy to access in one convenient location. |
Why
should all cabling be tested?
Every
cable, whether a new installation or a move from another location,
should be tested according to the appropriate TIA standards to ensure
proper functionality for today's applications, as well as for future
requirements. |
When
is fiber optics a consideration?
Fiber
optics may be a viable option in many instances. First, for distance
purposes, since Category 5 copper cable has a distance limitation
of 90 metres. Secondly, fiber optics is immune to electromagnetic
interference due to the fact that it carries only light, and no electrical
impulses. Depending on where the cable is to be installed, electrical
influences may be a factor. And thirdly, it may be considered in situations
requiring increased bandwidth. Fiber optic cable has much greater
capacity than copper cable in terms of speed and complexity of communications
transmission. |
What
is wireless N series ?
Wireless-N
products were specifically engineered for growing businesses like
yours. Utilizing draft 802.11n (Wireless-N) and Multiple-In/Multiple-Out
(MIMO) antenna array technologies, they feature the fastest speeds
that now exceed 100Mbps Ethernet it support up to 300Mbps speed and
indoor 75m & 300m in out door. Wireless-N and MIMO provide a substantial
increase in indoor wireless coverage, so “dead spots” in
your building can be eliminated and all your employees can stay connected
to the network and to each other. Wireless-N is also backwards compatible
with your legacy 802.11b and 802.11g devices. |
What
do you mean by ADSL connection ?
Asymmetric
Digital Subscriber Line (ADSL) is a form of DSL, a data communications
technology that enables faster data transmission over copper telephone
lines than a conventional voiceband modem can provide. It does this
by utilizing frequencies that are not used by a voice telephone call.
A splitter - or microfilter - allows a single telephone connection
to be used for both ADSL service and voice calls at the same time.
Because phone lines vary in quality and were not originally engineered
with ADSL in mind, it can generally only be used over short distances,
typically less than 3mi (5 km).
At the telephone exchange the line
generally terminates at a DSLAM where another frequency splitter
separates the voice band signal for the conventional phone network.
Data carried by the ADSL is typically routed over the telephone
company's data network and eventually reaches a conventional internet
network. In the UK under British Telecom the data network in question
is its ATM network which in turn sends it to it's IP network IP
Colossus. |
What
is ADSL 2+ ?
ADSL2+
extends the capability of basic ADSL by doubling the number of downstream
bits. The data rates can be as high as 24 Mbit/s downstream and 1
Mbit/s upstream depending on the distance from the DSLAM to the customer's
home.
ADSL2+ is capable of doubling the
frequency band of typical ADSL connections from 1.1 MHz to 2.2 MHz.
This doubles the downstream data rates of the previous ADSL2 standard
of up to 12 Mbit/s, but like the previous standards will degrade
from its peak bitrate after a certain distance. |
Wi
- Max ?
WiMAX,
the Worldwide Interoperability for Microwave Access, is a telecommunications
technology aimed at providing wireless data over long distances in
a variety of ways, from point-to-point links to full mobile cellular
type access. It is based on the IEEE 802.16 standard, which is also
called WirelessMAN. WiMAX allows a user, for example, to browse the
Internet on a laptop computer without physically connecting the laptop
to a router, hub or switch via an Ethernet cable. The name WiMAX was
created by the WiMAX Forum, which was formed in June 2001 to promote
conformance and interoperability of the standard. The forum describes
WiMAX as "a standards-based technology enabling the delivery
of last mile wireless broadband access as an alternative to cable
and DSL." |
