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Socket / Plug - Wiring
- Patch Cabling
Analog, Digital Voice
This category consists of basic telecommunications and
power-limited circuit cables. There are no electrical
performance test or bandwidth requirements for this classification.
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ISDN(Data), 1.44Mbps, T1(1.544 Mbps), Digital Voice
This category consists of cables specified to 1 MHz. |
10Base-T, ISDN, Voice
This is a performance designation for twisted-pair cable
and connecting hardware that can support frequency transmission
up to 16 Mhz, and data rates of 10 Mbps. Category 3 has
the capability to support low speed data applications,
performing to the acceptable minimum for 100 ohm cabling
systems; however it is now primarily used for telephone
wiring. |
10Base-T, ISDN, Voice
This category consists of cables and connectors specified
up to 20 MHz and data rates of 16 Mbps. Since the development
of Category 5, Category 4 wiring systems are rarely used.
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100 MHz solution
Suitable for 10BaseT, 100BaseTX, 16Mbps Token ring and
155ATM
Ideally used in applications where high bandwidth is unlikely
to be required |
100 - 155MHz solution
Suitable for Gigabit Ethernet, 10BaseT, 100BaseTX, 16Mbps
Token Ring and 155/622ATM
Ideally used for higher bandwidth applications |
200Mhz + solution
Suitable for all above applications
This is the maximum future proofing available for structured
cabling today. |
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Now, bear with me, you need to understand some of this
stuff...
The 10BASE-T and 100BASE-TX Ethernets consist of two
transmission lines. Each transmission line is a pair
of twisted wires. One pair receives data signals and
the other pair transmits data signals. A balanced line
driver or transmitter is at one end of one of these
lines and a line receiver is at the other end. A (much)
simplified schematic for one of these lines and its
transmitter and receiver follow:
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Pulses of energy travel down the transmission line
at about the speed of light (186,000 miles/second).
The principal components of one of these pulses of energy
is the voltage potential between wires and current flowing
near the surface of the wires. This energy can also
be considered as residing in the magnetic field which
surrounds the wires and the electric field between the
wires. In other words, an electromagnetic wave which
is guided by, and travels down the wires.
The main concern is the transient magnetic fields which
surrounds the wires and the magnetic fields generated
externally by the other transmission lines in the cable,
other network cables, electric motors, fluorescent lights,
telephone and electric lines, lightning, etc. This is
known as noise. Magnetic fields induce their own pulses
in a transmission line which may literally bury the
Ethernet pulses, the conveyor of the information being
sent down the line.
The twisted-pair Ethernet employs two principle means
for combating noise. The first is the use of balanced
transmitters and receivers. A signal pulse actually
consists of two simultaneous pulses relative to ground:
a negative pulse on one line and a positive pulse on
the other. The receiver detects the total difference
between these two pulses. Since a pulse of noise (shown
in red in the diagram) usually produces pulses of the
same polarity on both lines one pulse is essentially
canceled by out the other at the receiver. Also, the
magnetic field surrounding one wire from a signal pulse
is a mirror of the one on the other wire. At a very
short distance from the two wires the magnetic fields
are opposite and have a tendency to cancel the effect
of each other out. This reduces the line's impact on
the other pair of wires and the rest of the world.
The second and the primary means of reducing cross-talk--the
term cross-talk came from the ability to (over) hear
conversations on other lines on your phone--between
the pairs in the cable, is the double helix configuration
produced by twisting the wires together. This configuration
produces symmetrical (identical) noise signals in each
wire. Ideally, their difference, as detected at the
receiver, is zero. In actuality it is much reduced.
The above was sourced from the 9th Tee
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The following is an excerpt from Ethernet:
The Definitive Guide by Charles Spurgeon (O'Reilly and
Associates, 2000):
“In late 1972, Metcalfe and his Xerox PARC colleagues
developed the first experimental Ethernet system to
interconnect the Xerox Alto, a personal workstation
with a graphical user interface.
The experimental Ethernet was used to link Altos to
one another, and to servers and laser printers. The
signal clock for the experimental Ethernet interface
was derived from the Alto's system clock, which resulted
in a data transmission rate on the experimental Ethernet
of 2.94 Mbps.
Metcalfe's first experimental network was called the
Alto Aloha Network. In 1973 Metcalfe changed the name
to "Ethernet," to make it clear that the system
could support any computer-not just Altos-and to point
out that his new network mechanisms had evolved well
beyond the Aloha system.
He chose to base the name on the word "ether"
as a way of describing an essential feature of the system:
the physical medium (i.e., a cable) carries bits to
all stations, much the same way that the old "luminiferous
ether" was once thought to propagate electromagnetic
waves through space. Thus, Ethernet was born.”
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| 10Base2 |
Is 10MHz Ethernet running over
thin, 50 Ohm baseband coaxial cable. 10Base2
is also commonly referred to as thin-Ethernet.
Limited to 185 meters (607 ft) per unrepeated cable segment.
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| 10Base5 |
Is 10MHz Ethernet running over standard
(thick) 50 Ohm baseband coaxial cabling.
Limited to 500 meters (1,640 ft) per unrepeated cable
segment. |
| 10BaseF |
Is 10MHz Ethernet running over fiber-optic
cabling.
depends on the signaling technology and medium used but
can go up to 2KM. |
| 10BaseT |
Is 10MHz Ethernet running over unshielded,
twisted-pair cabling.
Generally accepted to have a maximum run of 90M, but is
really based on signal loss in Db's (11.5db maximum loss
source to destination). |
| 10Broad36 |
Is 10MHz Ethernet running through
a broadband cable.
Limited to 3,600 meters (almost 2.25 miles). |
100BaseFX
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100-Mbps baseband Fast Ethernet
specification using two strands of multimode fiber-optic
cable per link. To guarantee proper signal timing,
a 100BaseFX link cannot exceed 400 meters in length.
Based on the IEEE 802.3 standard. |
| 100BaseT |
100-Mbps baseband Fast Ethernet
specification using UTP wiring. Like the 10BaseT technology
on which it is based, 100BaseT sends link pulses over
the network segment when no traffic is present.
However, these link pulses contain more information than
those used in 10BaseT.
Based on the IEEE 802.3 standard. Also known as Fast Ethernet.
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| 100BaseTX |
100-Mbps baseband Fast Ethernet
specification using two pairs of either UTP or STP wiring.
The first pair of wires is used to receive data; the second
is used to transmit. To guarantee proper signal timing,
a 100BaseTX segment cannot exceed 100 meters in length.
Based on the IEEE 802.3 standard. Also known as Fast Ethernet.
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| 100BaseX |
100-Mbps baseband Fast Ethernet
specification that refers to the 100BaseFX and 100BaseTX
standards for Fast Ethernet over fiber-optic cabling.
Based on the IEEE 802.3 standard. Also known as Fast Ethernet,
and IEEE 802.3. |
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ANSI "American National
Standards Institute" - A definer of standards
of all kinds, including FDDI.
Appletalk - A protocol family developed by
Apple Computer to implement LANs serving Macintoshes.
Bridge - A network "relay" which
reads, buffers, and sends data to relay it from one
data link to another, but makes the two data links
appear as one to levels higher than the data link
layer.
Dialup Modem - Modem used over ordinary dial-up
telephone lines as opposed to private or leased lines.
FTP - Protocol in the "TCP/IP" family
for copying files from one computer to another. Stands
for "File Transfer Protocol".
Gateway - A type of "network relay"
that attaches two networks to build a larger network.
Modern "narrow" usage is that it is one
that translates an entire stack of protocols, e.g.,
translates TCP/IP-style mail to ISO-style mail. Older
usage used it for other types of relays--in particular,
in the "TCP/IP" world, it has been used
to refer to what many now insist is a "router".
NFS "Network File System" - an IP-based
protocol originally developed by Sun Microsystems
which provides file services.
Protocol - The "rules" by which two
network elements trade information in order to communicate.
Must include rules about a lot of mundane detail as
well as rules about how to recover from a lot of unusual
communication problems. Thus they can be quite complicated.
Relay - One terminology uses the term "relay"
as a device that interconnects LANs, different kinds
of relays being repeaters, bridges, routers, and gateways.
Repeater - In the "Ethernet" world,
a "relay" that regenerates and cleans up
signals, but does no buffering of data packets. It
can extend an Ethernet by strengthening signals, but
timing limitations on Ethernets still limit their
size.
Router - A network "relay" that uses
a protocol beyond the data-link protocol to route
traffic between LANs and other network links.
Routing Protocol - a protocol sent between
routers by which routers exchange information own
how to route to various parts of the network. The
TCP/IP family of protocols has a bunch, such as RIP,
EGP, BGP, OSPF, and dual IS-IS.
SMTP "Simple Mail Transfer Protocol"
- the protocol in the TCP/IP family used to transfer
electronic mail between computers. It is not oriented
towards a client/server system so other protocols
(see "POP") are often used in that context.
However, servers will use SMTP if they need to transfer
a message to another server.
SNMP "Simple Network Management Protocol"
- Originally developed to manage IP based network
equipment like routers and bridges, now extended to
wiring hubs, workstations, toasters, jukeboxes, etc.
SNMP for IPX and AppleTalk under development. Widely
implemented. See CMIP.
TCP/IP "Transmission Control Protocol/Internet
Protocol" - literally, two protocols developed
for the Defense Data Network to allow their ARPANET
to attach to other networks relatively transparently.
The name also designates the entire family of protocols
built out of IP and TCP. The Internet is based upon
TCP/IP.
TELNET - a protocol in the TCP/IP family that
is used for "remote login". The name is
also often used as the name of the client program
that utilizes the TELNET protocol.
Terminal Server - a network device that allows
a number of terminals to attach to a LAN, and do remote
logins across the LAN.
Token Ring - In the more general sense of the
word, a type of LAN that has stations wired in a ring,
where each station constantly passes a special message
(a "token") on to the next. Whoever has
the token can send a message.
Tunnelling - An important concept in the design
of many kinds of networks: taking some protocol-family's
ability to move packets from user to user, or to open
virtual-circuits between users, and use this as if
it were a data-link protocol to run another protocol
family's upper layers (or even the same protocol family's
upper layers). Examples: running TCP/IP over Appletalk
instead of something like Ethernet; running Appletalk
over DECnet instead of something like Localtalk or
Ethernet.
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