Home networking help
Home networking help: One of the first steps when you want to set up a network is choosing the right cables and connectors.
You may decide to set up a small network at home to play multi-player games or simply to share your printer and scanner. Whatever the reason is, there is, there is one very important decision to make before you can even consider setting up your network. Choosing the right cables and connectors can mean the difference between a decent network and a frustrating nuisance. Unless you want to walk into the store clueless, I suggest you take a little time investigating the different options available to you. This will help you make the right choice for your needs.
There are four main types of cables used in networking: Coaxial, Unshielded Twisted Pair, Shielded Twisted Pair and Fibre Optics. Each with advantages and disadvantages. It is important to consider what type of cable you intend using in your network. Your budget, security requirements, and distance of cable between nodes and where the cables will be installed determine the type of cable you use.
The more common of all the networking cables is coaxial cable. Coaxial cable has two conductors that share the same axis. Exist in Solid Copper Core or Stranded Wires. We classify Coaxial Cable by size and its resistance to direct or alternating electric currents. The table below outlines the different categories.
RG-8: THICKNET: 50 OHM
RG-58: THINNET: 50 OHM
RG-59 & RG-11: TV CABLE: 75 OHM
RG-62: ARCNET: 93 OHM
Let’s look at each of these:-
THINNET COAXIAL
Thinnet Coax is 2.5 inches thick. Often referred to as “Cheap Net” or 10Base2. Thin Net is less expensive than the other coax cable. It can carry a signal over 185 meters. Known as RG-58 Family with an impedance of 50 ohm. This would be your first choice if you were considering an inexpensive network. 185 meters is a fair distance for a network at home.
The next table outlines the different classifications of thinnet cable.
TYPES OF THINNET COAXIAL
RG-58 / U (50 ohm): Solid copper core
RG-58 A/U (50 ohm): Stranded Wire Core
RG-58 C/U: Military Specifications of RG-58 A/U
RG-59: Broad band Transmission (TV Cable)
RG-62 ( 93 ohm): ArcNet Network Cable
A thinnet cable will use BNC 50 OHM connectors. They are very easy to obtain in most computer stores and are inexpensive.
If you run into any trouble with your network using thinnet, first check that the cable terminator reads 50 ohm. If not, replace it. The second common problem is when the terminators are not securely fitted onto your NIC. A loose terminator will affect your network.
Bare in mind that you will be running a BUS network here. A bus network is literally a daisy chain. Each device is connected at intervals along a straight line with a terminator at each end. Do not attach too many devices to your network, keep it less than 10. That includes printers, scanners, fax machines and computers.
A bus network is prone to problems because one machine down will effect the entire network. But it is fairly simple to troubleshoot. Follow these steps and you are sure to isolate the problem.
Check terminator resistance. If there is a break in the cable, the resistance will not read 50 OHMs.
Remove the terminator on one end and attach it further down the network, cutting out the last device on your network. If the problem persists, move further down the network. You will soon find the computers are able to communicate with the devices left on the network. You have now found the problem device. By making the network shorter, you are isolating the source f the problem.
This brings me to my next point; a common network problem is the cable length. If you exceed the cable’s limit without repeaters, you will run into problems. Always check the cable length and number of devices on the network. Attenuation is the degradation of signal over distance. To avoid this keep within the limits.
Once you have isolated the problem, you can check whether the BNC connector is securely fastened and the NIC is not faulty.
It is very important that you do not run your network cables near other cables, behind television sets or radios. The Electromagnetic signals will interfere with the communication between devices. EMI as it’s called can cause the loss or corruption of data.
THICKNET COAXIAL
Thicknet is thicker than thinnet (0.5 inches) and can carry a signal up to 500 meters. Transceivers (vampire tap) are used to make physical connection with thicknet core. Unless you really need to run your network over 500 meters, this is not a good choice for a home network. The extra equipment needed and the cable itself is expensive.
UTP(UNSHIELDED TWISTED PAIR) is twisted pair wiring that is no shielded, thus susceptible to crosstalk. Crosstalk is the term used for overflow of signal across cables. Shielded twisted pair is twisted pair wiring but covered with protective foil, making it less susceptible to crosstalk.
Both carry a signal over 100 meters. UTPand STP are connected through a Hub. Your network will set laid out in a star fashion. One advantage of running a star network is the network will not go down if a machine goes down. You can easily add devices to a star network with relative ease. Twisted Pair cables use RJ connectors. Your telephone line uses a RJ connector. In the case of a telephone line, the connector is a RJ-11. Most networks use a RJ-45 connector.
UTP/ STP category Speeds
Category 1 Voice only
Category 2 4 mbps
Category 3 16 mbps
Category 4 20 mbps
Category 5 100 mbps
PVC and Phenum Cables
PVC
PVC is a flexible, inexpensive jacket for coaxial cable. It is used mainly in exposed areas
Plenum
Used in drop ceilings & between floors. It is fire resistant and does not give off poisonous fumes when burnt like PVC does. Like PVC, Phenum is used as a jacket for coaxial cable. It is certainly more costly, but is required by law to be used in ceilings.
Fibre optics
I do not want to spend too much time on Fibre optic cables. It is very unlikely you would be using this type of cable in your network at home. It is very difficult to install and is very costly.
Fibre Optic Cable carries light pulse signals through glass core. You would choose fibre optic cables if you are a speed junky. The signal transmits at 100 mbps – 200,000 mbps.
Fibre Optic cables is classified into multimode or single mode. In Multimode cable, the signals travel over multiple light paths. All parts of the signal arrive at the other end at the same time. Light emitting diodes are used (LED).
A Single mode cable allows single light pulses through. It is typically used for laser signalling. Light pulses are created by injection laser diodes (ILD)
Fibre Optic cable is differentiated by core or cladding size and mode. Size and purity of the core determine the amount of light that can be transmitted.
Now that we have looked at the different pros and cons of the different cables, you are well on you way to setting up your network at home. The next important thing to look at is the Network Interface Card. The cable you choose will dictate what type of NIC your able to use. Some NICs come standard with a certain type of connector; make sure it matches your cable. Your supplier should be able to advise you on this. If he can’t, find another supplier! Always check the manufacturer’s documentation making careful note of the Hardware Compatibility List.
