|
Networking
Basics:
Wiring and transmission Media
Describes three
common types of wiring media for Local Area Networks
There are three major forms of transmission media used
for LANs:
Twisted pair: Two insulated
copper wires twisted together in a regular spiral pattern;
one pair establishes one communication link; it transmits
electromagnetic signals. Twisted pairs are distinguished
between shielded and unshielded twisted pairs according
to their protection against electromagnetic fields
| Twisted
Pair Ethernet |
| Medium: |
2-pair
Category 5 Cable |
| Data
Rate: |
10
Mbit/s (10BASE-T),
100 Mbit/s (100BASE-TX)
|
| Segment
Length: |
max.
100 m (point-to-point) |
| Connection: |
RJ45
Connector |
Coaxial cable: a single
insulated inner wire is surrounded by a cylindrical
conductor which is covered with a shield; it transmits
electromagnetic signals. Coaxial cable is classified
into two categories: baseband (uses digital signals)
and broadband (uses analog signals) coaxial cable.
| Original
Ethernet |
| Other
Names: |
Yellow
Cable, Thickwire |
| Medium: |
Coaxial
cable |
| Data
Rate: |
10
Mbps |
| Segment
Length: |
max.
500 m |
| Users: |
max.
100 Tranceivers/segment |
| Termination: |
50
Ohm, 1 Watt |
| Connection: |
via
Tranceiver with Vampire tap |
Fiber Optic: consists
of three concentric sections, the core (a fibre conducting
optical rays), the cladding (reflecting optical rays)
and the jacket (surrounding one or many fibres to protect
them); transmitts optical signals, which must be transformed
to electromagnetic signals.
| Fiber
Optic Ethernet |
| Medium: |
2
Fiber Pairs
(50/125 or 62, 5/125)
|
| Data
Rate: |
10
Mbit/s (10BASE-FL),
100 Mbit/s (100BASE-FX)
|
| Segment
Length: |
max.
2000 m (point-to-point) |
| Connection: |
ST
Connector (10-BASE-FL)
Duplex SC Connector (100BASe-FX)
|
Each transmission media has its own advantages and
disadvantages. They differ in costs, capacity,
possible length, and electromagnetic isolation. Which
media to be chosen depends on three other characterization
features of LANs: firstly, which topology is to be implemented.
Secondly, which capacity and reliability are needed.
|
