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Cabling
Coaxial Cable:
Is more resistant to EMI electromagnetic interference, provides a higher bandwidth and longer cable lengths compared to twisted pair.
Can transmit using a baseband method, where the cable carries only one channel
Can transmit using a broadband method, where the cable carries several channels.
Twisted pair:
Is cheaper and easier to work with than coaxial cable.
STP Shielded twisted pair - Has an outer foil shielding which is added protection from radio frequency interference.
UTP Unshielded twisted pair - Different categories of cabling that have different characteristics.
Fiber-optic cabling:
Because of the use of glass, it has higher transmission speeds that can travel over longer distances and is not affected by attenuation and EMI when compared to cabling that uses copper. It does not radiate signals like UTP cabling and is very hard to tap into.
Is expensive.
Cabling problems:
Noise - The receiving end will not receive the data in the form that was originally transmitted. Can be caused by motors, computers, copy machines, florescent lightning and microwave ovens.
Attenuation - The loss of signal strength as it travels or caused by cable breaks and cable malfunctions.
Crosstalk - When electrical signals of one wire spill over to another wire. UTP is much more vulnerable to this than STP or coaxial.
Plenum space - Network cabling that is placed in an area to meet specific fire rating to ensure that it will not produce and release harmful chemicals in case of a fire.
Pressurized conduits - Encapsulation of wires so if there is an attempt to access a wire, the pressure of the conduit will change and sound an alarm or send a message to the administrator.
Types of transmission
Analog transmission signals - Modulation of signals, electromagnetic waves.
Digital transmission signals - Represents binary digits as electrical pulses.
Asynchronous communication - Two devices are not synchronized in any way. The sender can send data at anytime and the receiving end must always be ready. Can be a terminal and a terminal server or modem.
Synchronous communication - Takes place between two devices that are synchronized, usually via a clocking mechanism. Transfers data as a stream of bits.
Baseband - Uses the full cable for its transmission
Broadband - Usually divides the cable into channels so that different types of data can be transmitted at a time.
Unicast method - A packet needs to go to one particular system
Multicast method - A packet need to go to a specific group of systems
Broadcast method - A packet goes to all computers on its subnet
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