BuckingFastard
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If you have not read it, please see the previous installments of networking tutorials.
Networking 101
The following is a crash course in the inner workings of networking media and is meant for people who are interested in how data is transferred between devices, what the media is composed of, and different media's potentials.
Network Media Introduction
Essentially, all computers communicate with binary which is a combination of “0”s and “1”s. How the binary actually gets between the computers is a mystery to most people. Different media gets the data across in different ways, but each way is very similar; each type includes some type of pulse. When a pulse is received, it is interpreted as a “1”. When something is not being received, it is interpreted as a “0”.
The maximum distance of a specific type of media refers to the maximum amount of distance before the signal being sent is unreadable. The problem of too weak a signal can be solved by using a repeater. This device amplifies the signal back to its original strength. However after a while, the signal becomes so distorted that the repeater only amplifies the distortion.
In this case, you need what some call a “signal regenerater”. This is essentially a copy of what you have on the sending end. So if the signal is going between two switches and you have a regenerater in the middle, essentially its like putting another switch in the middle. This takes in the signal and re-transmits it in its original form.
Ethernet
Speeds Available – 10Mb/s, 100Mb/s, 500Mb/s (one direction, see below)
Maximum Distance – Depends on speed, usually around 100 meters (328 feet)
Cost – Very cheap to run and terminate cable, equipment relatively cheap
Ethernet came around in the 70's and 80's and although it was inferior to Token Ring up until around 1995, the high cost of Token Ring drove Ethernet to become the standard.
It 0 volts and 5 volts to represent “1”s and “0”s being sent across the wire.
Ethernet comes in two basic flavors: shielded (STP or Shielded Twisted Pair) and unshielded (UTP or Unshielded Twisted Pair). Both types include four twisted pairs of wires and an outside sheath. The difference between the two is that STP has a foil sheath surrounding the wires underneath the outside sheath. The twisting of the pairs helps prevent cross-talk between the wires.
There are three main catagories of Ethernet: CAT 5, CAT 5e, and CAT 6 (CAT is short for category). The difference between CAT 5 and CAT 5e is that CAT 5e is rated up to speeds of 1000Mb/s, while CAT 5 is only rated for speeds up to 100Mb/s.
CAT 6 is rated for speeds up to 1000Mb/s, however the difference between 6 and 5 is the shielding. In CAT 5/5e, each of the four twisted pairs is either unshielded or shielded by one foil. With CAT 6, each wire has its own seperate shielding. Although more expensive, CAT 6 can be useful in certain situations.
Everyone will say that the fastest Ethernet speeds are 1000Mb/s (one gigabit per second, gigabit ethernet). This is somewhat of a fallacy. Gigabit over ethernet requires the use of all eight wires. Normally with 10 and 100Mb/s, only four of the eight wires are used. The other four are used for grounding to prevent cross-talk.
Gigabit over ethernet has a maximum transfer speed of 125Mb/s per wire, which is 250Mb/s per pair, which is 500Mb/s per direction. In other words, you will only send and receive data at 500Mb/s, however the overall transfer rate of sending and receiving is 1000Mb/s. With 10 and 100Mb/s over ethernet, you are receiving 10 or 100Mb/s in both directions.
Token Ring
Speeds Available – Approximately 4Mb/s, 16Mb/s
Maximum Distance – 4Mb/s: 100 meters (328 feet) 16Mb/s: 77 meters (252 feet)
Cost – Quite expensive for necessary equipment, cheap to run and terminate cable
Token ring was introduced by IBM in 1981. Although it was surperior to Ethernet, its high cost drove Ethernet to become the standard.
It uses 0 volts and approximately 4 volts to represent “1”s and “0”s being sent across the wire. Additionally, a “token” is passed between the computers. Only the computer with the token can send data.
Fiber Optic
Speeds Available – 10Mb/s, 100Mb/s, 1,000Mb/s, 10,000Mb/s
Maximum Distance – Depends on cable type, anywhere from three feet to across country.
Cost – For only the wire, per foot it has the same cost as Ethernet. Terminating is very expensive.
Note that fiber has a sending and a receiving wire. This means that, unlike Ethernet, you can attain speeds of 1000 or 10,000Mb/s sending and receiving, not divided between both.
Fiber was introduced in the 60's and 70's. Because of its high distance potential, fiber became very popular with phone companies such as Bell in the 70's and 80's and makes up a great deal of the Internet today.
One disadvantage of fiber is that it is very sensitive. Things such as dirt and dust can easily have an effect on your network. This is why the connectors of fiber are always cleaned with a special tool before being plugged in.
Fiber is composed of a glass core which can vary in size, a cladding which reflects the light inside the wire, and an outside coating. It uses pulses of light to represent “1”s and “0”s being sent across the wire.
Fiber has two main flavors: multi-mode and single-mode. Each has its distinct advantages and disadvantages.
Multi-mode fiber is generally orange in color and has a wider glass core. Multiple signals can be sent through the wire at one time. It uses an LED to produce the light and has a shorter distance.
Single-mode fiber is generally yellow in color and has a much smaller glass core. Only one signal can be sent through at a time. It uses a powerful laser to produce the light and has a much, much longer distance potential than multi-mode fiber.
When being run long distances, fiber-optic cable must be manufactured to perfection. Every imperfection in the glass core or cladding causes the signal to become distorted. Over long distances, this can easily impede the cable's performance.
Wireless
Speeds Available – 11Mb/s, 54Mb/s, 108Mb/s
Maximum Distance – Depends on type of wireless, usually around 30 meters (100 feet)
Cost – Can be expensive to set up multiple computers, generally cheap enough for the average home user
801.11a – 54Mb/s, transmits at 5GHz, shorter range than b/g
802.11b – 11Mb/s, transmits at 2.4GHz, can have interference from 2.4GHz phones and microwaves
802.11g – 54Mb/s, transmits at 2.4GHz, can have interference from 2.4GHz phones and microwaves
With certain propriatary technology, speeds of 108Mb/s can be reached.
As far as security goes, WEP (Wired Equivalent Privacy) is good enough for the average home user. Pease note that WEP is not very good and can be broken with time. However it'll keep the local wardriver away from your network.
If security is really your concern, consider WPA2. WPA2 is stronger than WEP and has not been broken.
Well, that's it for Networking 102. Stay tuned for the next installment! Comments/criticisms welcome!
Networking 101
The following is a crash course in the inner workings of networking media and is meant for people who are interested in how data is transferred between devices, what the media is composed of, and different media's potentials.
Network Media Introduction
Essentially, all computers communicate with binary which is a combination of “0”s and “1”s. How the binary actually gets between the computers is a mystery to most people. Different media gets the data across in different ways, but each way is very similar; each type includes some type of pulse. When a pulse is received, it is interpreted as a “1”. When something is not being received, it is interpreted as a “0”.
The maximum distance of a specific type of media refers to the maximum amount of distance before the signal being sent is unreadable. The problem of too weak a signal can be solved by using a repeater. This device amplifies the signal back to its original strength. However after a while, the signal becomes so distorted that the repeater only amplifies the distortion.
In this case, you need what some call a “signal regenerater”. This is essentially a copy of what you have on the sending end. So if the signal is going between two switches and you have a regenerater in the middle, essentially its like putting another switch in the middle. This takes in the signal and re-transmits it in its original form.
Ethernet
Speeds Available – 10Mb/s, 100Mb/s, 500Mb/s (one direction, see below)
Maximum Distance – Depends on speed, usually around 100 meters (328 feet)
Cost – Very cheap to run and terminate cable, equipment relatively cheap
Ethernet came around in the 70's and 80's and although it was inferior to Token Ring up until around 1995, the high cost of Token Ring drove Ethernet to become the standard.
It 0 volts and 5 volts to represent “1”s and “0”s being sent across the wire.
Ethernet comes in two basic flavors: shielded (STP or Shielded Twisted Pair) and unshielded (UTP or Unshielded Twisted Pair). Both types include four twisted pairs of wires and an outside sheath. The difference between the two is that STP has a foil sheath surrounding the wires underneath the outside sheath. The twisting of the pairs helps prevent cross-talk between the wires.
There are three main catagories of Ethernet: CAT 5, CAT 5e, and CAT 6 (CAT is short for category). The difference between CAT 5 and CAT 5e is that CAT 5e is rated up to speeds of 1000Mb/s, while CAT 5 is only rated for speeds up to 100Mb/s.
CAT 6 is rated for speeds up to 1000Mb/s, however the difference between 6 and 5 is the shielding. In CAT 5/5e, each of the four twisted pairs is either unshielded or shielded by one foil. With CAT 6, each wire has its own seperate shielding. Although more expensive, CAT 6 can be useful in certain situations.
Everyone will say that the fastest Ethernet speeds are 1000Mb/s (one gigabit per second, gigabit ethernet). This is somewhat of a fallacy. Gigabit over ethernet requires the use of all eight wires. Normally with 10 and 100Mb/s, only four of the eight wires are used. The other four are used for grounding to prevent cross-talk.
Gigabit over ethernet has a maximum transfer speed of 125Mb/s per wire, which is 250Mb/s per pair, which is 500Mb/s per direction. In other words, you will only send and receive data at 500Mb/s, however the overall transfer rate of sending and receiving is 1000Mb/s. With 10 and 100Mb/s over ethernet, you are receiving 10 or 100Mb/s in both directions.
Token Ring
Speeds Available – Approximately 4Mb/s, 16Mb/s
Maximum Distance – 4Mb/s: 100 meters (328 feet) 16Mb/s: 77 meters (252 feet)
Cost – Quite expensive for necessary equipment, cheap to run and terminate cable
Token ring was introduced by IBM in 1981. Although it was surperior to Ethernet, its high cost drove Ethernet to become the standard.
It uses 0 volts and approximately 4 volts to represent “1”s and “0”s being sent across the wire. Additionally, a “token” is passed between the computers. Only the computer with the token can send data.
Fiber Optic
Speeds Available – 10Mb/s, 100Mb/s, 1,000Mb/s, 10,000Mb/s
Maximum Distance – Depends on cable type, anywhere from three feet to across country.
Cost – For only the wire, per foot it has the same cost as Ethernet. Terminating is very expensive.
Note that fiber has a sending and a receiving wire. This means that, unlike Ethernet, you can attain speeds of 1000 or 10,000Mb/s sending and receiving, not divided between both.
Fiber was introduced in the 60's and 70's. Because of its high distance potential, fiber became very popular with phone companies such as Bell in the 70's and 80's and makes up a great deal of the Internet today.
One disadvantage of fiber is that it is very sensitive. Things such as dirt and dust can easily have an effect on your network. This is why the connectors of fiber are always cleaned with a special tool before being plugged in.
Fiber is composed of a glass core which can vary in size, a cladding which reflects the light inside the wire, and an outside coating. It uses pulses of light to represent “1”s and “0”s being sent across the wire.
Fiber has two main flavors: multi-mode and single-mode. Each has its distinct advantages and disadvantages.
Multi-mode fiber is generally orange in color and has a wider glass core. Multiple signals can be sent through the wire at one time. It uses an LED to produce the light and has a shorter distance.
Single-mode fiber is generally yellow in color and has a much smaller glass core. Only one signal can be sent through at a time. It uses a powerful laser to produce the light and has a much, much longer distance potential than multi-mode fiber.
When being run long distances, fiber-optic cable must be manufactured to perfection. Every imperfection in the glass core or cladding causes the signal to become distorted. Over long distances, this can easily impede the cable's performance.
Wireless
Speeds Available – 11Mb/s, 54Mb/s, 108Mb/s
Maximum Distance – Depends on type of wireless, usually around 30 meters (100 feet)
Cost – Can be expensive to set up multiple computers, generally cheap enough for the average home user
801.11a – 54Mb/s, transmits at 5GHz, shorter range than b/g
802.11b – 11Mb/s, transmits at 2.4GHz, can have interference from 2.4GHz phones and microwaves
802.11g – 54Mb/s, transmits at 2.4GHz, can have interference from 2.4GHz phones and microwaves
With certain propriatary technology, speeds of 108Mb/s can be reached.
As far as security goes, WEP (Wired Equivalent Privacy) is good enough for the average home user. Pease note that WEP is not very good and can be broken with time. However it'll keep the local wardriver away from your network.
If security is really your concern, consider WPA2. WPA2 is stronger than WEP and has not been broken.
Well, that's it for Networking 102. Stay tuned for the next installment! Comments/criticisms welcome!
