Network Cables
The first time a LAN (Local Area Network) using a wire "coaxial". Then, the cable "twisted pair" is used in the telephone system has been able to bring a higher frequency and can support LAN traffic. And this time, fiber optic cable has been featured as a very high-speed cable pilhan.
Local Area Network using four types of cables:
- coaxial
- Unshielded Twisted Pair (UTP)
- Shielded Twisted Pair (STP)
- Fiber Optics
1. Coaxial Cable
Coaxial Cable consists of :
- a copper conductor
- wrapping layer with a "ground wire".
- an outermost layer
Use of Coaxial Cable
Coaxial cable is sometimes used for bus topology, but some products are not supporting LAN coaxial cable connection.
Ethernet LAN protocol that was developed using coaxial cable:
10Base5 / Cable "Thicknet":
- RG/U-8 is a coaxial cable.
- cable is "original" Ethernet.
- not be used again for the modern LAN.
10Base2 / Cable "Thinnet":
- RG/U-58 is a coaxial cable.
- has a smaller diameter than "Thicknet".
- replace "Thicknet".
- no longer recommended, but is still used in a very small LAN networ
2. Unshielded Twisted Pair (UTP)
Cable "unshielded twisted pair" (UTP) is used for LAN and telephone system. UTP cable consists of four pairs of each color copper conductor twisted pair. Packaging protects the cable and provides a path for each pair of wires. UTP cable connected to the device via the 8 pin modular connectors called RJ-45 connectors. All LAN protocols can operate over UTP cable. Most devices are equipped with LAN RJ-45.
UTP category
There are 5 categories (levels) for UTP cables. This category supports voice signal low speed (low-speed voice) and high-speed LAN signal. Category 5 UTP category recommended as the minimum for LAN installation and suitable for the star topology. The following table shows each category:
Category |
Performance (MHz)
|
Aplication
|
Cat 1
|
1
| Voice, Mainframe, Dumb Terminal |
Cat 2
|
4
| 4 MB Token Ring |
Cat 3
|
10
| 10MB Ethernet |
Cat 4
|
20
| 16 MB Token Ring |
Cat 5
|
100
| 100 MB Ethernet |
3. Shielded Twisted Pair (STP)
"Shielded twisted pair" is a type of phone cord is used in several installations business. There is an additional wrapper for each pair of wires ("twisted pair"). STP cable is also used for network data, use on the IBM Token-Ring. Wrapper can provide better protection against EMI interference.
Weakness of STP cable
STP cable has several drawbacks:
- Increased attenuation at high frequencies.
- At high frequencies, so that the balance can not compensate for the decreased incidence of "crosstalk" and signal "noise".
- The price is quite expensive.
4. Fiber Optic Cables
Fiber Optic cable is the latest cable technology. Made of optical glas. In the middle there is a cable glas filaments, the so-called "core", and surrounded by a layer of "cladding", "buffer coating", reinforcing materials, and protective luar.Informasi transmitted using light waves by converting electrical signals into light waves. Transmitter is widely used LED or Laser.
Excess use Fiber Optic Cable
Fiber Optic cable has several advantages, including:
- Large bandwidth capacity (gigabit per second).
- Further transmission distances (2 to more than 60 kilometers).
- Immune to electromagnetic interference.
Fiber Optic Cables are widely used on the WAN network for voice and data communications. The main obstacle in the use of fiber optic LAN cables are electronic devices that are still expensive. While the price of its own optic fiber cable is proportional to the UTP LAN cable.